In a large skillet over medium heat, drizzle a little oil and add seasoned boneless, skinless chicken breasts. Cook for about 6-7 minutes on each side until the chicken turns golden brown and reaches an internal temperature of 165°F (74°C). Once done, remove from the skillet, allow to cool slightly, and shred the chicken with two forks.

While the chicken is cooking, bring a large pot of salted water to a rolling boil. Add the elbow macaroni and cook according to the package instructions until al dente, usually around 7-9 minutes. Drain all the water and set the pasta aside.

In the same skillet used for the chicken, melt 4 tablespoons of butter over medium heat. Once melted, sprinkle in 4 tablespoons of flour, whisking continuously for about 1-2 minutes to form a roux. Gradually whisk in 2 cups of milk, continuing to cook for 3-4 minutes until the mixture thickens and becomes creamy.

Slowly add 1 cup of cheddar cheese and 1 cup of mozzarella cheese to the thickened milk mixture, stirring until melted and smooth. Taste the cheese sauce to ensure it's perfectly seasoned; add salt and pepper according to your preference.

Once the cheese sauce is ready, stir in the shredded chicken and cooked elbow macaroni. Pour in your desired amount of BBQ sauce to coat everything evenly. Stir the mixture well.

Spoon the BBQ Chicken Mac and Cheese into bowls or a serving dish. For an extra touch, drizzle additional BBQ sauce on top and garnish with fresh herbs like parsley or chives.