Pastry for 9" pie
2 tbsp. butter
1 c. thinly sliced onions
3 eggs, slightly beaten
1/2 c. grated cheese
2 tsp. prepared mustard
1 1/2 tbsp. flour
1 can cream of mushroom soup
1/2 c. milk

Line pie plate with pastry. Saute onions until tender, not brown. Spread over pastry. Sprinkle with grated cheese.

Blend all other ingredients together. Pour over onions and cheese. Bake at 350 degrees for 45-60 minutes. Test with a knife for doneness. Egg beaters can be used in place of eggs.