**note...i used a red onion because i am poor at the moment and that is the only onion i had laying around.
5-6 fist-sized potatoes, washed and sliced.
3 tbsp. butter
1 onion, diced
3 tbsp flour
1 1/2 cups milk (i use unsweetened soy, and it's just as tasty)
2 1/4cups cheddar cheese (i've used soy cheese, and it's alright. it doesn't melt properly for the topping, though)
**red pepper flakes
**= if you like it a bit spicy.
*melt butter over medium heat. add onion, saute until just soft. add flour, stir and cook for one minute. stir in milk, raise heat slightly. cook, stirring until this thickens. remove from heat, stir in 1 1/2 cups of the cheese, pepper and red pepper flakes (if you want them). stir until cheese melts.
*place 1/2 of the sliced potatoes in a baking dish. cover with half of the sauce, dust with paprika, add rest of potatoes, cover with the remaining sauce. dust with paprika and optional cayenne. sprinkle with remaining cheese.
*bake at 375 for 45 minutes uncovered. cover with foil and bake 15 minutes more.
p.s. a secret? you can use this exact cheese sauce for macaroni and cheese. just leave out the onion, chop up some spinach, stir with al dente pasta, cover with breadcrumbs and bake at 375 until bubbly.