Cheesy Potatoes With Onions - cooking recipe

Ingredients

3 lbs russet potatoes (peeled and thinly sliced, about 6 medium)
2 medium onions, thinly sliced
1 (6 ounce) package sliced process American cheese
salt and pepper
1 1/4 cups cheddar cheese, shredded
1/4 cup butter
1/4 cup flour
1 pinch cayenne pepper (or to taste)
3 cups warm full-fat milk

Preparation

Set oven to 400 degrees.
Butter a 13 x 9-inch baking dish.
Cook the sliced potatoes in boiling water for about 5 minutes; drain.
Layer one-third of the partially-cooked potatoes in bottom of the baking dish, then one-third of onion slices, then one-third of the cheese slices.
Sprinkle with salt and pepper, then repeat layers two more times.
Sprinkle top with the shredded cheddar.
For the sauce; in a medium heavy saucepan melt butter over low heat.
Add in flour and cayenne then stir for 1 minute.
Slowly add in milk; whisk or stir until bubbly and thickened (about 3 minutes).
Pour the sauce over the cheese and potato mixture.
Bake for about 35 minutes or until golden.
Let stand for 10 minutes before serving.