Preheat the smoker to 225 F.: The air fills with a calm, warm draft as the smoker comes up to 225 F , creating a steady environment that lets smoke infuse gently. You want the heat consistent rather than spiking, because a low and slow finish encourages the cheese to meld without separating. A common mistake is starting too hot, which can cause the top to crust quickly while the interior stays under warmed. If your smoker runs hot, aim for a slightly lower rack placement or reduce vents to stabilize the temperature.
Cook the elbow pasta until al dente. Drain and toss through the olive oil.: As the elbow macaroni boils, watch for the moment when it is tender but still has a slight chew, a texture that will hold up through smoking. Drain promptly to prevent water dilution of the sauce, then toss with the olive oil so the noodles remain separate and glossy. Listen for the quiet clatter of the colander and notice the steam rising, a cue that it is hot enough to absorb sauce. Overcooking is the main pitfall here, so test a piece by biting it to ensure resilience.
Combine the two cheeses and separate two cups of the cheese for the topping. Combine the milk and half and half together.: Mixing the shredded cheddar cheese and smoked gouda gives you an even distribution of flavor; set aside two cups for a final topping that will brown and smoke on the surface. Combining the milk and half and half creates a uniform dairy base that heats evenly when added to the roux. Keep the dairy cold until use to avoid graininess when it meets hot fat. A misstep is adding cold cheese directly into a scorching liquid, which can lead to clumping, so measure and prep first.
Melt butter in a saucepan over medium heat. Whisk in the flour. Slowly add in the milk/half-and-half mixture, whisking constantly until smooth. Continue adding the remaining milk/half-and-half in. Continue letting everything simmer together until it has thickened.: The butter should foam gently before you add the flour , creating a pale roux that smells mildly nutty but not browned. When you stream in the combined dairy, whisk continuously so the sauce stays emulsified and lump free. As the mixture heats, you will notice the sauce becoming silkier and the aroma becoming richer, a sign the starches are blooming properly. Simmer gently rather than boiling, because too high heat will break the emulsion and make the sauce grainy. A frequent error is rushing and adding cold liquid too quickly, which invites lumps; patience here yields a velvety texture.
Remove from the heat. Add the salt and pepper and slowly fold in 1 1/2 cups of the cheese and let it melt naturally. Once melted, add another 1 1/2 cups until completely smooth.: Off the heat the sauce carries gentle steam, and the residual warmth is perfect for melting cheese without overheating. Sprinkle in the salt and pepper to brighten the base, then fold in the measured portions of cheese so they melt gradually, producing a glossy, cohesive sauce. You will see the sauce become thicker and silkier as the cheese integrates, releasing a savory dairy perfume. If you add the cheese too fast or return to high heat, the fats can separate, so take your time and allow each addition to melt fully before the next. Avoid vigorous boiling now, as that can change texture detrimentally.
In a large mixing bowl, add the cooked pasta and mix through the cheese sauce until fully combined. Fold through the remaining one cup of cheese.: Transfer the warm elbow macaroni into a bowl and pour the sauce over it, stirring so every noodle is lacquered in the creamy mixture. Folding in the last cup of cheese at this stage ensures pockets of melty strands throughout the dish, creating textural contrast. The combined aroma of cheddar cheese and smoked gouda will be mellow and inviting, and the pasta should look glossy and cohesive. A common slip is stirring too aggressively, which can crush the pasta, so fold gently but thoroughly.
Transfer the mix into a large cast iron skillet. Place the skillet in the smoker, close the lid, and smoke for an hour.: Spoon the cheesy pasta into a pre oiled large cast iron skillet so it bakes evenly and develops a slightly caramelized edge. As the skillet sits in the smoker at 225 F , you will notice a delicate, wood kissed aroma lifting from the surface and small bubbles appearing at the edges. The cheese will lightly brown and form a pleasing skin while the interior stays luxuriously creamy. Resist opening the smoker too often, because stable smoke and heat are what coax the flavor in. If you leave the skillet in too long or increase the heat, the sauce can separate or dry out, so monitor time carefully and remove once the top is set and lightly bronzed.