Saute garlic and onion in shortening in skillet. Mix salt, pepper and flour. Dredge beef with seasoned flour. Add to onion mixture. Brown lightly. Add mushrooms, catsup and ½ cup bouillon. Simmer, covered, for 30 minutes, adding more bouillon as needed. Add sour cream. Simmer for 30 minutes. Alternate layers of beef mixture and noodles in casserole. Refrigerate, covered, overnight. Sprinkle with poppy seed. Bake at 325 degrees for 30 minutes, adding more bouillon if necessary.