In a skillet or sauté pan, melt butter and coconut oil over medium-high heat. Add sliced shallots, cooking about 3 to 4 minutes until soft and turning golden.
Add the bread crumbs and stir to coat with oil. Season with salt and pepper.
Sprinkle topping over casserole.
Bake for 25 to 30 minutes, until the bread crumbs are golden brown and the cream sauce is bubbling.