Preheat your oven to 350°F (180°C, gas mark 4). Bring a large pot of water to a boil and add 1 teaspoon of salt. Add the dry macaroni and cook for 1 minute less than the package direction for al dente, about 8 to 9 minutes. Drain the macaroni well and return to the pot. Stir in 3 tablespoons of butter until melted; this prevents the noodles from sticking together.

While the macaroni cooks, melt the remaining 3 tablespoons of butter in a large, shallow cast-iron pot or Dutch oven over medium heat. Sprinkle in the flour and whisk constantly for 1 minute until the mixture becomes slightly golden and frothy. This base will help thicken your cheese sauce.

Slowly whisk in the milk and half and half to the butter and flour mixture, pouring gradually to prevent lumps. Continue to cook on medium heat, whisking continuously, until the sauce thickens—about 5 to 8 minutes. Once thickened, remove the pot from heat and add the American cheese, shredded sharp orange cheddar, white cheddar, Romano, and Parmesan cheese. Stir until all the cheese has melted and the sauce is smooth. If the cheese isn't fully melted, you can return the pot to a low flame. Season the sauce with additional salt and black pepper, adjusting to your taste. I like to taste at this stage and add a bit more pepper for a gentle kick.

Add the drained, buttered macaroni (from Step 1) to the pot with the cheese sauce (from Step 3). Stir well until every noodle is thoroughly coated in the creamy cheese sauce.

Sprinkle the remaining 1/2 cup shredded orange cheddar and 1/2 cup shredded white cheddar evenly over the top of the macaroni and cheese mixture. Transfer the pot (or pour the mixture into a prepared baking dish) to the oven and bake uncovered at 350°F (180°C) for 15 minutes, until the sauce is bubbling and the cheese on top is melted. For a crispier, browned top, place the casserole under the broiler for an additional 2 to 3 minutes, keeping a close eye to prevent burning. I like to broil it just until the cheese is golden for extra flavor.

Remove the macaroni and cheese from the oven and let it cool for about 10 minutes before serving. This rest time allows the cheese sauce to set, making it easier to scoop. Optionally, garnish with a sprinkle of black pepper and freshly chopped parsley if you like a fresh finish. Enjoy while warm!