Add salt and add macaroni and cook until not quite al dente (macaroni will continue to cook in the oven).In another pot melt the butter, add the flour and stir with a whisk or a wooden spoon for a couple of minutes to cook the flour.
Add the milk, 1/2 cup at a time whisking until the mixture thickens, then add remaining milk and let cook over low heat until the sauce thickens, stirring constantly, scraping from the bottom of the pan and being careful not to burn it at the bottom.When the sauce is thick add the grated cheeses and stir until melted. Stir in the nutmeg, hot pepper sauce and salt, remove from heat and set aside.When the macaroni is cooked drain into colander and return to the pot.
Pour the cheese sauce over the macaroni and stir with a wooden spoon.
Pour the macaroni into individual gratins or a large buttered baking dish. You can add a few tomato slices into the macaroni either half way through pouring it into the pan or at the end, tucking them in with a knife. Don't smooth out the top, allow a few peaks here and there, they will become crisp and delicious as you bake it.To make the topping:Melt the butter, pour over the bread crumbs in a bowl and mix to combine.
Sprinkle topping over macaroni, bake in 400 oven 10-15 minutes or until crumbs are nicely golden.
