Boil water in a large pot and add a pinch of salt. Once the water is at a rolling boil, add the elbow macaroni and cook according to the package instructions. Drain and set aside.

In a medium saucepan, melt the butter over medium heat. Whisk in the flour to create a roux—cook for about 1 minute until bubbly.

Gradually add the milk while continuously whisking to prevent lumps. Cook until the sauce thickens, about 5 minutes.

Stir in the cheddar and mozzarella cheeses until melted and creamy. Season with salt and pepper.

In a large bowl, combine the cooked macaroni, shredded chicken, and BBQ sauce. Pour your cheese sauce over the mixture and stir well to combine everything evenly.

Transfer the mixture to a baking dish or simply serve it right away! Top with optional garnishes like green onions or bacon bits for added texture and flavor.