Ground Beef Stroganoff

We had this last night and it was really really good. It has a creaminess you don't usually get with dairy free.

* 1 large onion, chopped
* 8 ounces sliced mushrooms
* 1 pound lean ground beef
* 1tsp corn starch
* 1 can beef broth
* 1 teaspoon garlic powder
* 1 teaspoon salt
* 2 tablespoons ketchup
* 1 cup (8 ounces) Tofutti better then sour cream
* Half a regular size box of medium sized pasta shells.

Preparation:
Brown ground beef; drain off excess fat. Add onion, mushrooms, salt, garlic powder, ketchup, and 1/2 can of broth. Cook and stir until onions are soft and liquid has reduced somewhat; Mix 2 tbsp broth with corn starch. While stirring, add remainder of broth to the pan, then add corn starch mixture. Stir in sour cream and heat through. Add cooked pasta and serve.