This is the SOP at Mom’s Christmas Table, as the potato side dish.

Ingredients

• 2 tbsp. chopped onion
• ¼ cup butter*
• ¼ cup flour
• 1 tsp. salt
• ½ tsp. dry mustard
• Dash ground black pepper
• 1½ c. whole milk
• 2 c. (8 oz.) shredded mild cheddar cheese
• 6 c. cooked potato chunks, slightly undercooked

Directions

The day before …

1. Saute onion in butter.
2. Blend in flour and seasonings.
3. Gradually add milk: cook, stirring constantly, until thickened.
4. Add 1½ c. of the cheese; stir until melted.
5. Toss potatoes in the cheese sauce.
6. Pour into 2-quart casserole; refrigerate

The day of …

1. Bake in the oven on low for 2-4 hours, to slowly warm through and finish cooking the potatoes.
2. Top with remaining cheese. Serve.

Servings: 6; notations on the recipe call to triple the recipe for our holiday table.

Source: Something from Kraft foods

Notes:

* Original recipe calls for Parkay margarine, but, c’mon …

Variant: As the original recipe shows, this is meant as a main dish, using ½ lb. ham cut into 1/8-inch slices, and slicing the potatoes. In that arrangement, you end up tossing all but 1 cup of of potatoes into the casserole, “arranging” the ham and remaining potatoes, and baking at 350°F, 30 minutes, then topping with remaining cheese.