2 tbsp. butter
1 med. yellow onion, peeled and thinly sliced
2 tbsp. all-purpose flour
1 c. milk
1 tbsp. prepared spicy brown mustard
1/4 tsp. black pepper
2 c. cubed cooked ham
2 hard-cooked eggs, sliced

Preheat the oven to 350 degrees. Melt the butter in a 1-quart saucepan over moderate heat. Add the onion and cook, uncovered, for 5 minutes or until soft. Reduce the heat to low. Blend in the flour, slowly add the milk and cook, stirring constantly, until the mixture is thickened and smooth, about 3 minutes.

Remove the pan from the heat, and stir in the mustard and pepper. Pour half the sauce into an ungreased 1-quart casserole. Add a layer of the ham, then a layer of half the eggs. Repeat the layers of ham and eggs, then pour the remaining sauce over all. Bake, uncovered, 20 minutes or until the sauce is bubbly.