– 3 tablespoons butter (salted), divided – 1 small red onion, minced – 1 supermarket rotisserie chicken, minced and shredded finely – ½ teaspoon pepper – 1 teaspoon minced parsley – ⅓ cup all-purpose flour – 1 cup milk (whole or skim) – 1 teaspoon salt, (or to taste) – 2 egg (medium), beaten – 2 cup breadcrumbs, or panko – 3 cup oil for frying