1 c. fresh or canned sliced mushrooms, drained
1/2 c. chopped onion
2 tbsp. butter
1/3 c. sour cream
1 1/2 lb. ground beef
3/4 c. oatmeal
1 egg
2 tsp. salt
1/4 tsp. pepper
1 tsp. Worcestershire sauce
2/3 c. milk

For filling, lightly brown mushrooms and onions in butter in medium sized skillet. Remove from heat; stir in sour cream. For meat loaf, combine all remaining ingredients thoroughly. Place half of meat mixture in shallow baking dish. Make a shallow well for the filling. Spoon filling into well. Shape remaining meat mixture over filling, making sure all filling is covered. Bake in preheated oven 350 degrees for about 1 hour.