Make pie crust out of crushed Ritz crackers and 4 tsp. melt4ed butter. Press on bottom of pie pan. Saute onions in 2 tsp butter until slightly golden brown and limp. Pour on top of pie crust. Combine milk, eggs, salt and pepper. Pour over onions. Sprinkle cheese on top. Combine bread crumbs and 2 T. butter. Sprinkle on top of pie. Bake at 350f for 35 - 45 minutes or until set. Serve warm.