I was looking for a "grown up" macaroni and cheese recipe and this is what I came up with after reading a few different recipes and combining the best parts of each, this is what I came up with! It's a favorite and I always double the recipe for leftovers!
Cook the macaroni in a large pot of liberally salted water a few minutes short of al dente.
While the pasta cooks, melt butter in a large sauce pan over medium heat. In another sauce pot, heat milk (DO NOT BOIL). Add 3 tablespoons of flour. Cook the roux, stirring constantly, until thickened and nutty in color about 3 minutes. Pour in the hot milk and wisk constantly until thickened and the sauce coats the back of a spoon, about 5 minutes. Season lightly with salt, pepper and nutmeg. Stir in the cheeses a handful at a time and continue to stir until melted. Stir in the macaroni until evenly incorporated.
Grease large baking dish (or four 6 inch mini-skillets or six 12 inch ramekins) with butter. Add macaroni and cheese mixture, mounding the top. Sprinkle top of dish with remaining raclette and breadcrumbs. Drizzle 1-2 tablespoons melted butter.
If using large baking dish, bake 25 minutes or until golden brown and bubble. If using individual ramekins, bake 15 minutes. Let sit for 5 minutes and serve!
This is a great make ahead dish you can freeze and bake off when you need it. I sometimes make this and put it in individual loaf pans, freeze and give it to friends and family - they always look forward to it!