Step 1: Cook the Macaroni: Cook the elbow macaroni according to package directions until al dente. Drain well and set aside.
Step 2: Prepare the Roux: In a large saucepan or Dutch oven, melt the butter over medium heat. Whisk in the flour and cook for 2-3 minutes, stirring constantly, to create a smooth roux. This will help thicken the cheese sauce.
Step 3: Create the Cheese Sauce: Gradually whisk in the milk, ensuring there are no lumps. Bring to a simmer, stirring constantly, until the sauce begins to thicken. This process typically takes about 5-7 minutes.
Step 4: Season the Sauce: Stir in the salt, pepper, and nutmeg. Adjust seasonings to taste.
Step 5: Melt the Cheese: Reduce heat to low and gradually add the cheddar, Gruyere, Monterey Jack, and Parmesan cheeses, stirring continuously until the cheese is completely melted and the sauce is smooth and creamy.
Step 6: Combine Macaroni and Cheese Sauce: Add the cooked macaroni to the cheese sauce and stir until well coated.
Step 7: Prepare for Smoking: Preheat your smoker to 225F (107C). Choose your preferred wood chips for smoking (hickory or applewood are recommended).
Step 8: Smoke the Mac and Cheese: Pour the mac and cheese into a greased cast iron skillet or baking dish. Place the skillet or dish in the smoker and smoke for 30-45 minutes, or until the top is golden brown and bubbly, and the mac and cheese is infused with smoky flavor.
Step 9: Let it Rest and Serve: Remove from the smoker and let rest for 5-10 minutes before serving. This allows the sauce to thicken slightly.
Optional Tip: For an extra layer of flavor, sprinkle breadcrumbs mixed with melted butter on top before smoking.