Presoak mushrooms in a bowl with warm water for 1 hour.

Remove mushrooms with a slotted spoon; rinse, drain, and discard soaking liquid.

Place the rinsed and drained mushrooms in a pot filled with 13 cups of water; bring to a boil, reduce heat, and simmer for 10 minutes. Remove from heat.

Remove the mushrooms and let them cool (reserve the broth). Once the mushrooms are cool, chop them up.

Place the chopped mushrooms in a well-oiled frying pan and simmer them, stirring frequently.

Grate the carrots and add to the mushrooms. Simmer them together for 10 minutes, stirring constantly to prevent sticking.

Add the mushrooms and carrots back to the mushroom broth, bring to a boil, and let it cook for 5 minutes.

Add salt to taste.

Add pasta to the cooking pot and cook until pasta is ready. Serve hot, garnishing each serving with 1 tbs of non-dairy sour cream.