Preheat oven to 350 degrees F. Grease a medium casserole dish or medium glass baking dish with butter.
In a large bowl, combine the bell pepper, onion, and celery. Add the crabmeat and shrimp, and then the mayonnaise, salt, pepper, and Worcestershire sauce, tossing gently with a plastic spatula to combine. Spoon the mixture into the prepared dish. Sprinkle crumbs over top. Bake until a golden brown crust develops, about 30 minutes.
Recipe courtesy of Paula Deen