3/4 cup breadcrumbs
2 tbsp. unsalted butter
1/4 tsp. black pepper
1/4 tsp. salt
2 cups shredded cooked chicken
1 tsp. dried mustard, optional
2 cups grated cheddar cheese
2 cups whole or 2% milk
3 tbsp. all-purpose flour
1/4 cup unsalted butter
1 clove garlic, minced
1/2 sweet onion, chopped
8 oz. dry macaroni