Grilled Mac and Cheese

Just got home early this afternoon off a trip and needed something that wouldn't take hours to prepare and a trip to the grocery store. Happened to have a whole chicken laying around (doesn't everyone?) for which I would make Flat Iron Chicken, and the makings for a souped up Mac and Cheese on the grill.
Preheat your grill to about 350 degrees F.
Quarter your red and green peppers and place on grill, cooking until tender and sporting some very nice grill marks. Remove, dice and set aside
While your pasta is boiling; cut, grate and measure all your other ingredients and set aside.
When pasta is "al-dente" drain and set aside.
In a large saucepan (you can probably use the same one you used for the pasta) melt the butter and whisk in flour to thicken.
Add half of the milk (1cup) and whisk in. Begin adding cheeses one at a time whisking until thoroughly blended. If sauce becomes too thick begin adding milk.
Once the cheese is blended add in the black pepper, cayenne pepper and macaroni and blend thoroughly. Place in a 9x13 inch baking dish, sprinkle with bread crumbs and place in covered grill, heating indirectly. This is accomplished by turning off the gas burner on one side or moving the coals to one side, placing the dish on the cool side. Heat for about 12 minutes and serve warm.