Cheese Sauce keeps breaking?

i sprinkle about 1 tablespoon of flour in the bottom of my glass baking casserole and also I always use whole milk and salted butter. Use a russett potato since it is starchy and slice them really thin with a madoline slicer.

You need to make a white sauce before adding the cheese to the milk.

OR< assemble it all w/o heating the milk, and let the oven do the work. The starch from the potatoes ought to tighten it up (bake w/ foil on first 35 min or so)


Basic White Sauce
2 tablespoons butter
2 tablespoons all-purpose flour
1 cup milk

In a small saucepan over medium heat, melt butter. Add flour and stir until the butter and flour are well combined. Pour in milk, stirring constantly as it thickens. Add more or less milk depending on desired consistency.

Cheese Sauce:
To hot white sauce, stir in 1 cup of shredded cheddar cheese, stirring over low heat until melted.