Thaw and drain spinach - squeeze out all liquid. Reserve liquid.

Melt butter in saucepan over low heat. Add flour, stirring until blended and smooth. Add onion and sautee 5 minutes. Add liquid slowly, stirring constantly to avoid lumps. Cook until smooth and thick. Add seasonings and cheese. Stir until melted. Add spinach.

Serve immediately or place in casserole dish, top with bread crumbs, refrigerate and let sit overnight. Reheat when ready to serve. (This recipe also freezes well.)

For Thanksgiving or big gatherings, triple this recipe.