Cook the pasta

• Bring a large pot of salted water to a boil.
• Cook the macaroni until al dente, then drain.

Make the cheese sauce

• Melt the butter in a saucepan over medium heat.
• Whisk in the flour and cook for 1 min to form a roux.
• Pour in the milk gradually, whisking until smooth and thickened.

Melt in the cheese

• Remove from the heat and stir in the cheddar and mozzarella until melted.
• Season with salt and black pepper.

Combine and serve

• Add the drained macaroni to the cheese sauce and stir to coat.
• Serve hot.