Preheat your oven to 360°F (180°C). In a large mixing bowl, combine the shredded Cheddar cheese, Gruyere cheese, and Mozzarella cheese. Toss together and set aside-this ensures even distribution throughout your McAlister mac and cheese.

Bring a large pot of generously salted water to a rolling boil. Add the macaroni and cook to al dente texture, about 1-2 minutes less than the package instructions indicate. This prevents mushy pasta once baked. Drain thoroughly and set aside.

In a large saucepan over medium-low heat, melt the butter completely. Sprinkle in the flour and whisk continuously to form a smooth roux. Continue cooking for 2-3 minutes, whisking constantly to prevent burning and to cook out the raw flour taste.

Gradually pour in the milk, about 1 cup at a time, whisking vigorously after each addition until completely smooth. Continue cooking the sauce, stirring frequently, until it thickens slightly-about 5-6 minutes. The sauce should coat the back of a spoon.

Reserve about 1/4 of your cheese mixture for topping. Gradually add the remaining 3/4 of the cheese blend to the sauce, adding one handful at a time. Whisk until each addition is fully melted before adding more. Season with salt, black pepper, and nutmeg, stirring to incorporate.

Add the drained macaroni to the cheese sauce, folding gently until every piece of pasta is evenly coated with the creamy mixture. This ensures authentic McAlister’s mac and cheese flavor in every bite.

Transfer the mac and cheese to your prepared 12-inch baking dish, spreading it evenly. Sprinkle the reserved cheese blend across the top. Bake for 20-25 minutes until the top is golden brown and the edges are bubbly. Let rest for 5 minutes before serving.