hamburger stroganoff

1 lb. lean ground beef 1 med. onion, chopped 1 T. Cornstarch 1/4 cup cold water 1 tsp. garlic powder 1 tsp. salt 1/2 tsp. black pepper 2 cans cream of mushroom soup 1 (16 oz.) pkg. dried egg noodles 1 cup sour cream (or plain yogurt) Brown beef and onion in skillet till meat is done and onion is transparent. Drain grease. Dissolve cornstarch in cold water and pour onto meat. Stir in garlic powder, salt & pepper and soups. Cook for five minutes, stirring constantly. Reduce heat to low and simmer for another 10 minutes. Meanwhile, cook noodles according to pkg. directions. When done, drain . Remove meat mixture from heat and stir in sour cream and mix well. Add to noodles and mix till well blended.