Step 1

Bring a large pot of salted water to a boil. Cook the pasta to al dente according to the package instructions (if you plan to do the optional bake time, the pasta needs to be very al dente). Once it’s done cooking, drain it through a colander, and rinse.

Step 2

Add the egg to a small bowl, then beat it.

Step 3

Heat a large saucepan over medium heat, add the butter and let it melt. Once melted, sprinkle in the flour and mix to create a roux. Cook the roux for 2 minutes while stirring to prevent burning.

Step 4

While constantly whisking, pour in the milk and sprinkle in the mustard powder. Continue whisking occasionally while you simmer it until the sauce is very thick (about 5 minutes). Once thickened, reduce the heat to low.

Step 5

Take 1/4 cup of thickened sauce and slowly add it to the beaten egg while constantly whisking to prevent the egg from scrambling. Once smooth, slowly pour the egg mixture into the sauce while whisking constantly (it’s important to add it slowly so that the egg whites don’t curdle).

Step 6

Once the egg is incorporated into the sauce, add the shredded cheese, salt, seasoned salt, and pepper. Mix until the cheese is melted. Taste the cheese sauce and add more salt and seasoned salt to taste.

Step 7

Add in the cooked macaroni, and stir to coat it with the sauce.

Step 8

Optional: If you want baked mac and cheese, you can transfer it to a greased casserole dish. Top it with more cheddar cheese, then bake it for 20 to 25 minutes in a 350F oven.