Preheat oven to 375 degrees. Butter 84 one-ounce ramekins. In a small pan over medium heat, melt 2 tablespoons butter; toss with bread in a medium bowl.
Heat milk over medium heat until just steaming. Melt remaining butter in a deep skillet over medium heat. When butter bubbles, stir in flour; cook, stirring, 1 minute. Whisking constantly, slowly pour in hot milk, bring to a boil, and cook until thick enough to coat back of spoon.
Remove from heat. Stir in nutmeg, cayenne, 3 cups cheddar, 1 1/2 cups Gruyere, salt, and pepper. Stir in macaroni.
Pour into ramekins. Sprinkle with remaining cheeses and breadcrumbs. Bake until browned, about 30 minutes.
I wonder if paper medicine cups would work? I've seen them used for cupcakes before.
Something like this: http://www.foodservicewarehouse.com/solo-cup/scc-100/p336998.aspx (or just google "pleated paper medicine cup")
hot ramekins straight from the oven would burn the guests, if the ramekins cool so does the macaroni and cheese.....
Does anyone know where can I get ramekins like that? They are really nifty.