Prepare the Mixture : In a large bowl, combine crab meat, chopped shrimp, breadcrumbs, egg, mayonnaise, mustard, lemon juice, herbs, and seasoning. Mix gently until just combined.
Shape the Cakes : Divide mixture into equal portions. Shape into small patties and chill briefly to firm up.
Cook the Cakes : Heat oil or butter in a skillet over medium heat. Cook cakes until golden on both sides and cooked through.