I've even tried the microwave version, and it isn't all that bad, but trust me, this one is worth the work involved:

1 lb pasta --cooked to just tender and tossed with 1T butter
2c grated sharp Cheddar
1 inch wedge of Roquefort crumbled
1c grated Parmesan
1 tsp dry mustard (Colman's)
2T flour
2 c warm milk
salt/pepper/garlic/cayenne

White sauce: Saucepan over med-low heat, melt 2T butter. When butter is foaming, stir in 2T flour. Cook for a couple of minutes (keep stirring) then add 2 cups warm milk and whisk into a sauce. Add mustard, and salt/pepper/cayenne/garlic powder to taste. Stir in the cheeses and keep stirring until it's all melted. Pour sauce over pasta BEFORE putting it in the casserole dish. Top with buttered bread crumbs and bake at 350 for 45 minutes, or until the top is crusty.

~JE