Step 1

In a large pot, bring 2 quarts of salted water to a boil. Add pasta and cook until pasta is al dente, about 7 minutes. Remove from heat and strain out the water with a colander. Set aside.

Step 2

In a large skillet, melt the vegan butter over medium heat. Add onions, garlic, and mushrooms and sauté for about 5 minutes, stirring frequently, until the juices are released and onions and mushrooms are slightly browned. In a liquid measuring cup mix together the water with the Yondu vegetable umami. Add one cup of the Yondu broth to the onion/mushroom mixture along with the salt. Bring to a boil then reduce heat to a simmer. Simmer for 15 minutes until portobellos have reduced about 25% in size.

Step 3

In a small bowl combine the remaining 1 cup of Yondu broth with 3 tablespoons of flour. Mix until all the flour is dissolved. Add to the onion/mushroom mixture and bring to a boil, stirring constantly. Boil for 1-2 minutes, until you have a thick creamy sauce. Remove from heat and stir in the sour cream. Toss with prepared pasta and serve immediately with fresh parsley.