Mix the crabmeat, egg, bell pepper if using, green onions, mayonnaise, mustard, salt, pepper and bread crumbs. You need enough bread crumbs to hold the mixture together but you want the crab cake to be mostly crab so start with a tablespoon at a time and mix it together, adding a spoonful now and then and stop as soon as it holds itself together. Refrigerate 30 minutes or so.

Put the flour in a small shallow plate or dish and season with salt and pepper as you'd like. Some folks add curry powder. I did not.

Heat a large skillet and add the butter and oil, swirling the pan around until well coated after the butter melts.

Shape the mixture into 4 crab cakes, one at a time, dredging in flour and then adding to the pan. Cook about 4-5 minutes, turn, and then cook the other side another 4-5 minutes or so.