Saute green pepper in butter until translucent, but not brown.
Add to crabmeat, salt and pepper. Stir in mustard, mayonnaise and Worcestershire sauce. Put in buttered casserole. Top with bread crumbs, a few pats of butter, and sprinkle with crab boil seasoning.
Bake for 25 minutes in a preheated 375 degree F. oven.