Miso Mushroom Lasagna Soup: Love Without the Labour

"I made lasagna" might be the most romantic sentence in a home kitchen, because everyone who hears it knows what it cost. Somebody simmered a sauce all afternoon, boiled the sheets, laid them out on tea towels and built the layers one by one. Lasagna has always been love, measured in hours.

This soup keeps the feeling and hands you back the afternoon. Red lentil lasagna sheets cook directly in a tomato broth made deeply savoury by browned mushrooms, and the ricotta arrives on top in soft, whipped clouds instead of between layers. Everything happens in one pot in 50 minutes, and each bowl carries about 38 grams of protein. Two small decisions do all the heavy lifting: you leave the mushrooms alone, and you add the miso after the heat is off.

Ingredients

The soup

• 30 ml (2 tbsp) extra-virgin olive oil
• 250 g cremini mushrooms, thickly sliced
• 150 g shiitake mushrooms, stems removed, caps sliced
• 1 medium yellow onion (about 150 g), finely chopped
• 1 small fennel bulb (about 200 g), cored and finely chopped
• 4 garlic cloves, thinly sliced
• ¼ to ½ tsp red chilli flakes
• 30 ml (2 tbsp) tomato paste
• 1 can (796 ml) crushed tomatoes, no salt added if you can find it
• 1 L (4 cups) low-sodium vegetable or chicken broth
• ¼ tsp fine sea salt, plus more to taste
• 225 g red lentil lasagna sheets (made from 100% lentils)
• 100 g lacinato kale, stems removed, torn into bite-size pieces
• 100 g baby spinach (about 3 packed cups)
• 45 ml (3 tbsp) white (shiro) miso

No fennel? Use 1 celery rib and ½ tsp of crushed fennel seed. No shiitake? Use all cremini, or oyster mushrooms torn into strips.

The whipped ricotta

• 350 g whole-milk ricotta
• 30 g Parmigiano-Reggiano, finely grated (about ½ cup)
• Finely grated zest of ½ lemon
• 15 ml (1 tbsp) extra-virgin olive oil
• A pinch of fine sea salt

Dairy-free? Blend 350 g of medium-firm tofu with 30 ml olive oil, 15 ml lemon juice, 2 tbsp nutritional yeast and a pinch of salt until completely smooth, and leave out the Parmigiano.

To finish

• 15 ml (1 tbsp) extra-virgin olive oil
• A handful of fresh basil leaves
• Freshly ground black pepper and extra chilli flakes

How to make miso mushroom lasagna soup

1. Brown the mushrooms and leave them alone

Warm the 30 ml of olive oil in a heavy pot of at least 5 L over medium-high heat. Add the cremini and shiitake in a single layer and do not stir for 6 to 8 minutes, until the undersides are deep gold and the edges have gone dark. Stir once, then give them 3 more minutes. Browning needs a dry, hot surface, and every stir drops the temperature and lets the mushrooms steam in their own liquid. That dark crust is where the long-simmered flavour of this soup comes from.

2. Build the base

Lower the heat to medium. Add the onion, fennel and salt and cook for 5 minutes, until soft and translucent. Stir in the garlic, chilli flakes and tomato paste and cook for 2 minutes more, pressing the paste against the bottom of the pot until it turns brick red. Cooking the paste takes away its raw, tinny edge.

3. Add the tomatoes and the broth

Pour in the crushed tomatoes and the full litre of broth, scraping up anything stuck to the bottom. Bring to a boil, then lower to a steady simmer for 10 minutes. This is a good moment to whip the ricotta (step 6).

4. Break the lasagna sheets straight into the pot

Bring the soup back to a lively simmer. Snap the lasagna sheets into pieces of 5 to 7 cm and drop them in a few at a time, stirring so they do not stick together. Cook for 2 minutes less than the package suggests, usually 6 to 8 minutes, and stir often. Legume pasta goes from tender to soft quickly and keeps drinking broth after the heat is off, so it should still have a little bite at this point, and the starch it releases gives the broth its body.

5. Wilt the greens, turn off the heat, then add the miso

Stir in the kale and cook for 2 minutes, then add the spinach and stir for 30 seconds, just until it collapses. Turn off the heat. Whisk the miso with a ladle of hot broth in a small bowl until smooth, then stir it back into the pot. Boiling flattens miso's aroma and leaves only its salt behind, while whisking it first means you never find a lump of it in a spoonful. Stirred in at the end, it gives the broth a deep, savoury finish that tastes slow-cooked and Italian, and nobody at the table will guess there is a Japanese ingredient in it. Taste now, and add salt only if it needs it.

6. Whip the ricotta until it holds soft peaks

Combine the ricotta, Parmigiano, lemon zest, olive oil and a pinch of salt. Whisk hard for a minute, or pulse in a small food processor for 30 seconds, until glossy and light. Whipping smooths out the grainy curd and traps air, so the ricotta melts slowly into the broth instead of breaking into clumps.

7. Finish and serve

Ladle the soup into warm bowls and top each with two large spoonfuls of whipped ricotta, torn basil, a teaspoon of olive oil, black pepper and a few more chilli flakes. Adding the oil raw keeps its peppery aroma intact. Serve straight away.

Why this bowl works, component by component

Comfort food is usually built on refined flour and cheese, and then defended on the grounds that you only eat it occasionally. This one is built differently, and the reasons are worth knowing before you decide whether it earns a weeknight.

The pasta is the protein. A 56 g portion of dry red lentil pasta carries about 14 g of protein, roughly double what the same weight of wheat pasta provides, and it brings fibre that wheat pasta does not. With the ricotta and Parmigiano on top, a bowl lands at about 38 g of protein and 14 g of fibre, which is most of a day's fibre for many women in one sitting. Evidence: established, from food composition data.

The tomatoes get better for being cooked. When Cornell researchers heated tomatoes to 88°C, the bioaccessible trans-lycopene more than doubled within 15 minutes, although some vitamin C was lost along the way. Lycopene is fat-soluble, so the olive oil in the pot makes more of it available to you than a raw tomato would. Evidence: established for the chemistry; the long-term health effect of higher lycopene intake is still debated.

A dozen plants in one pot. Counting the mushrooms, this bowl holds around twelve different plant species: two mushrooms, onion, fennel, garlic, chilli, tomato, lentil, kale, spinach, basil, olive. The American Gut Project found that people who ate more than 30 types of plant a week had more diverse gut bacteria than those who ate 10 or fewer. It was an observational finding rather than a trial, but plant variety is one of the few dietary patterns that keeps turning up in microbiome research. Evidence: emerging.

The fat is the useful kind. Extra-virgin olive oil is made up mostly of monounsaturated fat, and it arrives here three times: in the pot, whipped into the ricotta and poured raw over the top. Fat in the bowl also slows how quickly the carbohydrate is absorbed, which is why this eats like dinner rather than like a bowl of pasta at nine o'clock.

The miso is for flavour, not for your gut. Miso is a fermented food, but a pot of hot soup is unlikely to leave live cultures intact, and we are not going to pretend otherwise. What it does do is replace a long simmer: fermentation has already built the savoury depth that tomato sauce normally needs an afternoon to develop. The trade-off is salt, which is where most of this bowl's 1,100 mg of sodium comes from. If that matters to you, use 30 ml instead of 45 and skip the added salt.

None of this makes a bowl of soup a health intervention. It makes it a dinner that behaves well: protein, fibre, plants and fat in the same bowl as the comfort.

Which miso should you use?

White (shiro) miso is the one to buy here. It is fermented for a shorter time than red or barley miso, which makes it sweeter and milder, so it deepens the tomato without taking over. Red miso works if it is what you have, but start with 30 ml, because it is saltier and more assertive. This recipe uses miso for its flavour. A pot of hot soup is unlikely to leave its live cultures intact, so there is no reason to pay more for an unpasteurised tub. For a gluten-free bowl, read the label closely: barley miso (mugi) contains gluten, and even rice-based miso is sometimes made in facilities that process barley.

For the mushrooms, choose cremini with closed caps that feel firm and dry, and shiitake caps that are thick and springy with no dark, wet patches. Wipe off any grit with a damp towel, or rinse quickly and dry them well. Wet mushrooms have to cook off that water before they can colour, which costs you most of the browning.

Tips from our kitchen

• If the mushrooms will not fit in one layer, brown them in two batches and combine them before step 2.
• Freeze the shiitake stems. They are too woody to eat but make excellent broth.
• Tear the kale into bite-size pieces. Long ribbons wrap around the pasta and make the soup awkward to eat.
• Keep a kettle hot. If the soup thickens more than you like before serving, loosen it with 125 ml of hot water or broth.
• A Parmigiano rind dropped in during the simmer adds more savoury depth. Take it out before serving, and leave it out if you are cooking for vegetarians.

Ahead of time, and afterwards

Cook the soup through step 3 up to three days ahead and refrigerate it, or freeze that base for up to four months. The ricotta can be whipped up to two days ahead and kept covered in the fridge. On the night, bring the base back to a simmer and pick up at step 4, and dinner is on the table in about 15 minutes.

Leftovers keep covered in the fridge for 2 to 3 days, which is Health Canada's guideline for soups, with the ricotta in a separate container. The pasta keeps absorbing broth, so by the next day the soup has thickened into something closer to a stew. Reheat on the stovetop with 125 to 250 ml of extra broth or water until steaming and 74°C (165°F) through, or cover and microwave in one-minute bursts, stirring between each. Thickened leftovers also make an excellent baked lasagna: spoon them into a baking dish, dot with the leftover ricotta and bake at 190°C (375°F) for about 20 minutes, until the edges bubble. Finished soup can be frozen, but the lentil pasta turns very soft once thawed.

Approximate nutrition per bowl

Calories	680
Protein	38 g
Fat	30 g, of which saturated 10 g
Carbohydrate	73 g, of which sugars 16 g (all naturally occurring)
Fibre	14 g
Sodium	1,100 mg

Based on one of four bowls, including the whipped ricotta and finishing oil. These figures are estimates calculated from Canadian Nutrient File and USDA FoodData Central values, and most of the sodium comes from the miso and Parmigiano.

Shop the story

• ORGANIKA Bone Broth Chicken Original, 300 g — $47.99. Mixed with hot water it stands in for the carton of broth, though the soup is then no longer vegetarian.

Frequently asked questions

Can I use regular wheat lasagna sheets?

Yes. Cook them for the time on the package, since wheat pasta is more forgiving than lentil pasta. Each bowl will drop to about 31 g of protein and lose a few grams of fibre.

What should I pour and serve with it?

A medium-bodied red with good acidity suits the tomato and mushrooms, such as Barbera, Chianti Classico or a cool-climate Canadian Pinot Noir. Serve a bitter green salad with lemon on the side, or grilled bread rubbed with a cut garlic clove.

Can I use frozen spinach or kale?

Yes. Use 150 g of frozen greens, thawed and squeezed dry, and add them with the tomatoes in step 3 so they have time to lose their frozen texture.

Can I double the recipe?

Yes, but use a pot of at least 7 L and brown the mushrooms in batches. Add the pasta in two rounds as well, so the pot comes back to a simmer quickly.

Can I make it in a slow cooker or Instant Pot?

In a slow cooker, brown the mushrooms and base on the stove first, then cook with the tomatoes and broth on low for 4 hours and add the pasta for the last 20 minutes on high. In an Instant Pot, do all the browning on the sauté setting, and cook the pasta on sauté too, because pressure cooking turns lentil pasta to mush.

Can I add meat?

Brown 450 g of Italian sausage, removed from its casings, after the mushrooms in step 1 and carry on as written. Ground turkey or chicken also works; season it with a little extra fennel seed so it tastes like sausage.

Sources

• Health Canada — Safe food storage
• Health Canada — Safe cooking temperatures
• Dewanto V, Wu X, Adom KK, Liu RH, "Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity", Journal of Agricultural and Food Chemistry, 2002 — PubMed
• McDonald D et al., "American Gut: an Open Platform for Citizen Science Microbiome Research", mSystems, 2018 — ASM Journals
• USDA — FoodData Central