Add 1 tablespoon oil into large saucepan. Saute the onion and green pepper until tender.
Over low heat in a medium saucepan, add butter and flour. Stir together. Slowly add half and half while whisking, about 2 minutes. Add ketchup, mustard and bread crumbs. Mix to combine. Allow to simmer for a few minutes. Add crabmeat and lemon juice. Season with salt and pepper, to taste.