- 6 small potatoes, peeled and cubed
- 3 tablespoons butter
- 2 cups cubed fully cooked ham
- 1 small onion, finely chopped
- 1/4 cup butter
- 3 tablespoons all-purpose flour
- 1 1/2 cups milk
- salt and ground black pepper to taste
- 1 (8 ounce) package shredded Cheddar cheese
- 1/4 cup bread crumbs
- Place potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, about 20 minutes. Drain.
- Preheat oven to 350 degrees F (175 degrees C).
- Grease a 1 1/2-quart baking dish.
- Melt 3 tablespoons butter in a skillet over medium heat. Stir in the ham and onion; cook and stir until the onion has softened and turned translucent, about 5 minutes.
- Stir potatoes into ham mixture; transfer to the prepared baking dish.
- Melt 1/4 cup butter in a saucepan over medium heat. Stir flour into melted butter until smooth.
- Gradually whisk milk into flour mixture; season with salt and black pepper. Continue cooking and stirring until thickened, about 2 minutes.
- Reduce heat to medium-low and stir Cheddar cheese into the white sauce until melted.
- Pour sauce over ham and potatoes.
- Sprinkle bread crumbs atop casserole.
- Bake in the preheated oven until sauce is bubbly and browned, 25 to 30 minutes.