1 tablespoons butter
3 tablespoons flour
2 cups milk, hot (not boiling)
1 1⁄4 cups grated American cheese
1 1⁄4 cups grated sharp cheddar cheese (for different variation, try using Monterrey jack cheese or adding 1/2 cup jalapeno slices)
1 lb elbow macaroni
Grease or spray with non-stick cooking spray a casserole dish.
Melt butter in medium saucepan.
When melted, add flour, stirring constantly for about 1 minute (until butter is absorbed).
Whisk in hot milk, cook for 3 minutes (stirring constantly).
Add 1 cup each of the cheeses, and stir until smooth.
Cook macaroni, drain, rinse under cold water, and drain again.
Combine everything together and pour into casserole dish.
Sprinkle the rest of the cheese on top, and bake at 400Ffor 20 minutes.