Beef Stroganoff

1 lb. Ground beef, browned and drained
1 medium onion, chopped (about ½ c.)
¼ c. butter
2 Tbsp. flour
1 tsp. salt
1 tsp. garlic powder or 1 clove garlic, minced
¼ tsp. pepper
1 can condensed cream of mushroom soup
1 c. sour cream
hot cooked egg noodles
Cook hamburger and onion in butter until onion is see-through. Stir in everything but soup, sour cream and noodles. Cook 5 minutes, stirring constantly. Remove from heat and stir in soup. Put back on heat and simmer on low, uncovered, for 10 minutes. Stir in sour cream; heat through. Serve over egg noodles.