MAKE THE LENTIL SAUCE: Heat 2 tablespoons extra virgin olive oil in a large pot. Add 1 onion, 1 rib celery, and 2 carrots, and sauté on medium heat for 3 minutes.Add 3 cloves garlic, 2 tablespoons tomato paste, ½ teaspoon rosemary, 2 bay leaves, and 8 ounces mushrooms grated with the large holes of a box grater.Season with 1 teaspoon salt and 2 twists of pepper, and cook on medium-high heat until the mushrooms release all their water and the pot dries.
Stir in 1 cup dried lentils (rinsed), 7 cups vegetable broth (you can add a few cups at a time), and 24 ounces (1 bottle) tomato puree.Simmer for 30 minutes or until the lentils are cooked. Then, discard the bay leaves and add 3 tablespoons balsamic vinegar. Taste and adjust for salt.Now, blend the soup until it reaches a coarse texture.Add more broth if necessary to achieve a soupy consistency.
ADD THE NOODLES: Break 8 -10 sheets lasagna noodles into 4 or 5 pieces. Cook pieces in salted boiling water until they are very al dente.We recommend adding a tablespoon of olive oil to the water to prevent the noodles from sticking together.Drain the noodles and add them to the pot with the lentil sauce. For a soupier dish, add more broth or water.
SERVING SUGGESTIONS: Serve in a bowl topped with a dollop of whole milk ricotta, shaved parmesan, thinly sliced scallions, fresh basil leaves, and a drizzle of extra virgin olive oil.
Servings: The lentil sauce quantities are for 8 servings. We recommend storing half away for meal prep and use the other half for this lasagna soup. Nutrition information is an estimate for 1 serving out of 4 servings with all toppings.SUBSTITUTIONSExtra virgin olive oil: Substitute another vegetable oil.Onion: Substitute 2 shallots for one onion.Rosemary: Substitute thyme or an Italian herb mix.Bay leaves: Substitute sage leaves.Mushrooms: We use brown button mushrooms. Substitute white mushrooms, baby bella, portobello, or any other mushrooms.Tomato puree: We use Italian tomato puree, also called passata. You can substitute canned crushed tomatoes, diced tomatoes, or San Marzano tomatoes.Dried Lentils: You can use brown, green, or French dried lentils.Balsamic vinegar: You can substitute soy or tamari sauce for balsamic vinegar.Lasagna sheets: You can substitute any pasta.Gluten-free: Substitute noodles for gluten-free lasagna noodles.Vegan: Substitute non-dairy cheese for ricotta and parmesan. Lasagna noodles might contain egg, but you should be able to find egg-free ones.STORAGELasagna soup's sauce can be stored separately from noodles to maintain quality.Store sauce in the fridge for up to 5 days or freeze for 3 months.Always cook noodles separately to prevent them from becoming mushy during storage.