Cheesy Squash Casserole

6 large yellow squash (cut into thin slices)
1 medium onion (sliced)
salt & pepper
1/2 cup sour cream
1 cup sharp cheddar cheese, grated
butter & cooking oil
ritz crackers (crushed for topping)

Place squash & onion in large skillet with cooking oil and tablespoon of butter, just enough to saute. Add salt & pepper and cook until veggies are tender. Remove from heat, add the cheese and sour cream and stir well. Pour into a greased 9 X 9 casserole dish. Top with crushed crackers. Bake at 350 for about 20 minutes or until golden brown and bubbly.