Buffalo-Chicken Macaroni and Cheese

INGREDIENTS

7 tbsp

unsalted butter, plus more for the dish

Kosher salt

1 lb

elbow macaroni

small onion, finely chopped

stalks celery, finely chopped

3 cups

shredded rotisserie chicken

2 cloves

garlic, minced

3/4 cup

hot sauce (preferably Frank's)

2 tbsp

all-purpose flour

2 tsp

dry mustard

2 1/2 cups

half-and-half

1 lb

yellow sharp cheddar cheese, cut into 1-inch cubes (about 3 1/2 cups)

8 oz

pepper jack cheese, shredded (about 2 cups)

2/3 cup

sour cream

1 cup

panko (Japanese breadcrumbs)

1/2 cup

crumbled blue cheese

2 tbsp

chopped fresh parsley