Cook the Pasta
Bring a large pot of salted water to a boil and cook the macaroni according to package directions until al dente. Drain well and set aside. Don't rinse the pasta - you want it to hold onto that cheese sauce!
Prepare the Roux
In a large saucepan, melt the butter over medium heat. Gradually whisk in the flour, stirring constantly until it becomes thick and clumpy. This roux is the foundation of your silky smooth cheese sauce.
Add Seasonings
Stir in the onion powder, paprika, garlic granules, Dijon mustard, and a good pinch of salt. Let these spices bloom in the roux for about 30 seconds - this is where the flavor really starts to build.
Create the Sauce Base
Pour in the milk one cup at a time, whisking constantly to prevent any lumps from forming. Keep stirring until the mixture is smooth and starts to thicken slightly. This takes a bit of patience, but it's worth it!
Incorporate the Cheese
Add half of the cheddar and Red Leicester cheese to the sauce, stirring until completely melted and smooth. The sauce should be creamy and have a beautiful golden color from the Red Leicester.
Combine Pasta and Sauce
Fold the cooked macaroni into the cheese sauce, making sure every piece is well coated. The pasta should be completely enveloped in that gorgeous, creamy cheese sauce.
Prepare for Baking
Transfer the mac and cheese to a buttered baking dish. Top with the remaining cheddar, Red Leicester, and all of the mozzarella cheese. This top layer will create an amazing golden, bubbly crust.
Bake to Perfection
Bake at 350°F for 15-20 minutes until the cheese is melted and bubbly. Then switch to the grill setting and cook for another 10 minutes to get that perfect crispy, golden top. Sprinkle with fresh parsley before serving.
