Heat the oven to 350 °F, then generously grease or spray a 9 X 11 baking dish. The coating should cover the bottom and corners so the browned crust releases cleanly.

Place the crumbled cornbread in a large mixing bowl and break up any large pieces with clean hands. Leave some small uneven crumbs for a more interesting, tender texture after baking.

Melt the butter in a skillet and cook the onions and celery for about 8 minutes, then whisk the eggs in a small bowl. The vegetables should be fully translucent, soft, and sweet-smelling before they meet the bread.

Fold the cooked vegetables, eggs, chicken broth, white bread cubes, poultry or Creole seasoning, mushroom soup, salt, and pepper into the cornbread, then transfer the mixture to the prepared dish and bake for 35 - 40 minutes. The top should turn golden, and the center should gently spring back when pressed with a spoon.