Ingredients

• 2 tablespoons butter or margarine
• 1 onion thinly sliced
• 2 tablespoons flour
• 1 cup milk
• 1 tablespoon mustard
• 1/4 teaspoon ground black pepper
• 2 cups cubed cooked ham
• 2 hard boiled eggs

Method 

Preheat oven to 350°F. Melt butter in a one quart saucepan over medium heat. Add the onion and cook, uncovered, until soft, about 5 minutes. Reduce heat to low. Blend in the flour and slowly add the milk. Cook, stirring constantly, until the sauce is thickened and smooth, about 3 minutes. Remove the pan from the heat and stir in the mustard and pepper. Pour half of the sauce into an ungreased one quart  casserole; add a layer of half of the ham, then a layer of half of the sliced eggs. Repeat the layers of ham and eggs, then pour the remaining sauce over the top. Bake uncovered about 20 minutes or until it starts to bubble.