I haven't fixed these since Andy's really been watching his carbs, but now that we have learned to control our portions and not eat the whole dish; I think we will treat ourselves to some this week.
4 medium-large potatoes
1 medium sweet onion (Vidalia when available)
Salt & pepper to taste
3 tbsp. butter
3 tbsp. flour
1/2 tsp. salt
2 cups milk
1-1/2 cups shredded Sharp Cheddar Cheese (or your preference)
Preheat oven to 400 degrees. Coat a small casserole dish with cooking spray or softened butter.
Peel potatoes and slice them to an equal thickness so they will cook evenly. (Between 1/8" to 1/4")
Slice onion and break up into rings.
Make a layer in the casserole dish with half of the potatoes and top with the onion slices.
Layer the remaining potatoes on top and season with salt & plenty of pepper to suit your taste buds.
Now comes the creamy, cheesy, yummy part. This is just like preparing any sauce or gravy. Melt the butter in a saucepan and whisk in the flour and salt. Keep stirring until well blended. Slowly add milk while continually whisking so you don't end up with lumps. As is starts to thicken, add the cheese and blend with a spoon until it's nice and creamy.
Pour that creamy goodness on top of the potatoes and onions. Cover with aluminum foil. Bake for about one and a half hours. Carefully check the doneness of the potatoes during the last fifteen minutes. Slowly remove the foil so you don't get burned by the steam. If your potatoes are done, put the dish back in the oven and let it bake so that the cheese sauce can "get a tinge of brown" like Andy says. If you cut your potatoes too thick and they require a lot more time, I'd cover them back up and check again fifteen minutes later.
Dig in!! Just try to pace yourself and don't overdo it.