3 lbs. zucchini
3 onions, chopped
1 stick butter
1/2 lb. fresh mushrooms (canned mushrooms are OK)

Slice zucchini into thin slices. Parboil in salted water, uncovered. Drain. Saute onions in butter. Add mushrooms and saute.

SAUCE:

2 tbsp. butter, melted
1/2 c. grated Cheddar cheese
1 tsp. seasoned salt
1 c. sour cream

Add cheese, seasoned salt and sour cream to melted butter. Mix with vegetables and heat through. Pour into 1 1/2 or 2 quart casserole.

TOPPING:

2 tbsp. grated Cheddar cheese
Crushed Ritz crackers

Sprinkle topping over all. Bake, uncovered, at 350 for 30 minutes.