Ingredients:
- 4 tablespoons unsalted butter, plus more for buttering the casserole dish
- 1 loaf brioche bread, cut or torn into 1 1/2-inch pieces
- 2 stalks celery, diced
- 2 leeks, diced
- Kosher salt and freshly ground black pepper
- 2 cups creamed corn
- 1 cup sour cream
- 4 large eggs