7 Tablespoons unsalted butter, plus more for the dish
1 pound elbow macaroni
1 small onion, finely chopped
2 stalks celery, finely chopped
3 cups shredded rotisserie chicken
2 cloves garlic, minced
3/4 cup Frank’s Buffalo Wing Sauce, divided
2 Tablespoons all-purpose flour
2 teaspoons dry mustard
2-1/2 cups half-and-half
1 pound extra sharp cheddar cheese, shredded
8 ounces pepper jack cheese, shredded
2/3 cup sour cream
1 cup panko (Japanese breadcrumbs)
1/2 cup crumbled blue cheese
2 Tablespoons chopped fresh parsley
Preheat oven to 350 degrees and butter a 9 x 13 baking dish. Bring a large pot of salted water to a boil; add the pasta and cook until al dente, about 7 minutes. Drain.
Meanwhile, melt 3 Tablespoons butter in a large skillet over medium heat. Add the onion and celery and cook until soft, about 5 minutes. Stir in the chicken and garlic and cook 2 minutes, then add 1/2 cup hot sauce and simmer until slightly thickened, about 1 more minute.
Melt 2 tablespoons butter in a saucepan over medium heat. Stir in the flour and mustard with a wooden spoon until smooth. Whisk in the half-and-half, then add the remaining 1/4 cup hot sauce and stir until thick, about 2 minutes. Whisk in the cheddar and pepper jack cheeses, then whisk in the sour cream until smooth.
Spread half of the macaroni in the prepared baking dish, then top with the chicken mixture and the remaining macaroni. Pour the cheese sauce evenly on top. Put the remaining 2 Tablespoons butter in a microwave safe bowl and microwave until melted. Stir in the panko, blue cheese and parsley. Sprinkle over the macaroni. Bake until bubbly, 30 to 40 minutes. Let rest 10 minutes before serving. Drizzle with some wing sauce for color.
Garnish with even more wing sauce, blue cheese and sour cream if you like!