Cook eggless noodles or pasta according to package directions and drain off the cooking water.
Sauté onions, garlic, and mushroom slices in vegan butter (or oil) and 1 tbsp of soy sauce over low heat for about 7 minutes until the onions become translucent and the mushrooms are tender.
Add 2 cups of vegan "beef" crumbles (you can add them frozen) (or homemade vegan ground beef) and cook for about 5 more minutes.
Stir in 1 1/2 cups of vegan sour cream (1 container) then stir in the vegan broth until you have a creamy soup-like texture.
Simmer until bubbly stirring the sauce frequently.
Mix in the cooked noodles and salt and black pepper to taste, then sprinkle with fresh parsley. Serve immediately. It's best when hot.
Notes
Saute your onions slowly over low heat to give them the best flavor.
Adjust the thickness of the sauce by adding slightly less or more broth.
The sauce will continue to thicken as the noodles absorb moisture and begin to cool. You can add a few tablespoons of water to it if it starts to thicken too much.
Add about 1/2 cup dry red wine - to give it a more complex flavor like a "beef" Burgandy type dish. (This is totally optional, but it gives it a great flavor).
Note: Not all wine is vegan. You can easily check to see if a brand is vegan by using the Barnivor guide to vegan alcohol.