3 1/2 TB flour
3 1/2 TB butter
1 tsp mustard powder
1 tsp fresh cracked black pepper
3C whole milk, heated not quite to boiling
maybe 12 oz worth of shredded cheese (I used a combination of plain old grocery store cheddar, with some cave-aged cheddar, smoked goat milk cheddar, and a 5-year-old cheddar)
Box of macaroni elbows
bread crumbs and a little additional shredded cheddar for topping
First cook the macaroni in salted water until it's a bit underdone, slightly harder than al dente (maybe 5 or 6 minutes for dried pasta), drain it and rinse it with cold water to stop the cooking.
You melt the butter in a sauce pan over low heat and then add the flour, mustard powder, and black pepper to make a roux. Let the roux cook a bit but you don't want to give it much color, just cook the flour so it doesn't taste quite so floury.
Then you use one hand to hold the pot handle, another hand to whisk constantly, and your third hand to slowly pour in the hot milk a little at a time. Once that hot milk hits the flour and butter, it binds up but you just keep stirring, making sure each addition of milk is fully incorporated before adding the next one, until it's all been added and you have a thin sauce. Then slowly add the shredded cheese, a small handful at a time, and let each addition melt before adding the next, until all the shredded cheese (except for the little bit you'll use for the topping) are added and you have a nice cheese sauce.
Combine the macaroni and the cheese sauce in a slightly buttered 9x13 pan until all the macaroni is covered in cheese sauce. pat it down so that it's level. Sprinkle a light coating of bread crumbs over the top and then a bit of shredded cheese, more to garnish than to coat.
Put it in the smoker for a couple of hours until it looks something like this (apologies for crappy cell phone pic):
My in-laws are visiting (they also thought it was delicious) and they got some pics too so if I'm able to get a better picture from them I'll post it. I've had a bug up my you-know-what to try this for a while and I'm glad I finally did!