buffalo chicken macaroni and cheese

buffalo chicken macaroni and cheese 7 tablespoons unsalted butter 1 pound (16 oz) elbow macaroni 1 small onion, finely chopped 2 stalks celery, finely chopped 3 cups shredded rotisserie chicken 2 cloves garlic, minced 3/4 cup Buffalo wing sauce (preferably Frank’s. If you are worried about the heat factor add half the amount) 2 tablespoons flour 2 teaspoons dry mustard 2 1/2 cups half-and-half 1 pound (16 oz) yellow sharp cheddar cheese, cut into 1-inch cubes (about 3 1/2 cups) 8 ounces pepper jack cheese, shredded (about 2 cups) 2/3 cup sour cream 1 cup panko breadcrumbs (found in the grocery store next to regular breadcrumbs) 1/2 cup crumbled blue cheese Preheat the oven to 350 degrees and spray a 9-by-13-inch baking dish with cooking spray. 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 separate saucepan over medium heat. Stir in the flour and mustard until smooth. Whisk in the half-and-half and add the remaining 1/4 cup hot sauce (less if you want it less spicy) and stir until thick, about 2 minutes. Whisk in the cheddar and pepper jack cheeses, then whisk in the sour cream until smooth. Combine the chicken mixture, cooked pasta, and cheese sauce and toss to combine. Put the remaining 2 tablespoons butter in a medium microwave-safe bowl and microwave until melted. Stir in the panko, blue cheese and parsley. Sprinkle over the macaroni and bake until bubbly, 30 to 40 minutes. Let rest 10 minutes before serving. Best served immediately.