I use this bread crumb topping recipe for many of the casseroles that I make, from vegetables in a cream sauce casseroles, to Mac and Cheese, to Mediterranean tomatoes, eggplant, zucchini casseroles. Even a pyrex baking dish of plain, canned green beans when topped with buttered bread crumbs, looks and tastes like way more effort and cost than it really is.
The funniest thing happens with casseroles with this crispy crumb topping. The top inch of the casserole gets taken, leaving the unadorned casserole or veggies, beneath, for "the next guy".
Simple and inexpensive -- about 6 cents worth of butter, plus about 4 cents worth of bread, total of 10 slim cents for a topping which really makes casseroles pop.
Crispy buttered bread crumb topping
In a small skillet, melt a generous tablespoon of butter, over Medium heat.
Tear 1 slice of bread into a food processor and pulse till crumbs.
Toss bread crumbs in the melted butter with a pinch of salt. Stir while sauteing, for about 1 minute.
Sprinkle over the casserole.
Toast, uncovered, in a 350 degree F oven for about 20 minutes. Serve.