12 frozen blintzes
1 lb. (or more) sliced mushrooms
2 lg. onions, chopped
1/2 pt. sour cream
1/2 lb. grated Cheddar cheese
1/2 lb. mozzarella cheese, grated

Saute mushrooms and onions in butter. Cool and drain. Mix in sour cream and put into greased 9 x 13 inch pyrex or square one. Layer blintzes in this fashion: 4 blintzes; 1/3 mushrooms, onion and sour cream; 1/3 Cheddar cheese; 1/3 mozzarella cheese. Repeat until all of the ingredients are used up. Bake at 350 degrees for 45-50 minutes. (Double if using rectangular dish.)