Brown meat. Remove to casserole dish. Add mushrooms, onions, garlic to skillet and cook 3-4 mins. Remove and add to casserole dish. Make sauce in skillet. Melt butter. Add flour, salt and tomato paste. Stir in beef bouillon and cook until thick. Stir in beef bouillon and cook until thick. Add sauce to casserole dish. Add sour cream and heat in 275 degree oven for 1/2 hour. Do not let it boil.