Step 1Heat the broiler or the oven to 350 degrees. Heat the milk to just below boiling and set aside.
Step 2Melt the butter in a saucepan. When it starts to bubble, whisk in the flour and cook for 1 minute to make a roux. Slowly pour the heated milk into the roux, whisking constantly, and cook until the mixture bubbles and becomes thick, about 15 minutes.
Step 3Remove from the heat and season with the salt, pepper, allspice, nutmeg and cayenne. Stir in the grated Cheddar, Fontina and Gruyere.
Step 4Cook the pasta in plenty of rapidly boiling salted water slightly less than you normally would, about 10 minutes. Stir the pasta into the cheese sauce and divide evenly among 6 buttered ramekins.
Step 5Divide the bread crumbs evenly among the ramekins and scatter over top. Brown the bread crumbs under the broiler 1 to 2 minutes or in the oven, about 30 minutes.