Clean and finely chop the portabella mushrooms. In a large pot, heat olive oil over medium-high heat. Add the chopped mushrooms and sauté for 8–10 minutes until tender.

Incorporate canned diced tomatoes, chopped fresh basil, and minced garlic into the pot. Cook for 3–4 minutes, stirring often, until fragrant.

Stir in canned crushed tomatoes, nutritional yeast, thyme, onion powder, oregano, and salt. Pour in vegetable broth or water, stirring well. Bring to a boil.

Once boiling, break lasagna sheets into small pieces and add to the pot. Stir to ensure noodles are submerged. Reduce heat to low, cover, and simmer for 20 minutes.

Check soup consistency; if thicker texture is desired, simmer uncovered for a few extra minutes. Serve hot with shredded cheese on top.