Start by boiling a large pot of salted water. Once boiling, add the 8 ounces of macaroni and cook according to the package instructions until al dente. Drain and set aside.
In a medium saucepan, melt 1/4 cup of butter over medium heat. Once melted, whisk in 1/4 cup of flour, stirring constantly for about 1-2 minutes until it forms a light golden paste. This is your roux.
Stir in 1/4 teaspoon of dry mustard, 1 teaspoon of salt, and 1/4 teaspoon of black pepper. This will add a delightful flavor to your cheese sauce.
Gradually whisk in 2 cups of milk, ensuring no lumps form. Continue to cook over medium heat until the mixture thickens, about 5-7 minutes.
Once the sauce is thickened, remove it from the heat and stir in 1 cup of American cheese until melted and smooth. This is where the magic happens, turning your sauce into a creamy delight.
Add the cooked macaroni to the cheese sauce, stirring until every piece is well-coated. At this point, you can taste and adjust seasoning if needed.
For a baked version, preheat your oven to 350°F (175°C). Transfer the macaroni and cheese to an oven-safe baking dish and bake for about 20 minutes until bubbly and slightly golden on top.