Fresh shrimp and crab cake burgers + a cool, creamy avocado sauce with a little hint of heat = love at first bite!
Rinse the shrimp, peel, and de-vein. Using a fork, break up larger chunks of crab. Combine the shrimp and crab in a large bowl, Mix in all the remaining ingredients, except for the butter. Form into 6 patties and set on a baking sheet lined with parchment paper. Chill for an hour. While the burgers are chilling, add all the ingredients for the Spicy Avocado Sauce to a blender or VitaMix and blend until smooth.
Heat the grill to medium. Place your cast iron skillet on the grill to preheat as well. When the temperature of the grill reaches 350 degrees, add the butter to the skillet.
Cook the patties 3-4 at a time, turning once. About 3 minutes per side. If the patties are browning too fast, turn the middle burner off (or bank your coals) and move the skillet to the middle. Alternatively, once you have turned the patties and both sides are browned, you can remove the skillet from the grill and cover. The crab cakes will continue to cook with the residual heat. Remove to a platter and keep warm while you finish cooking the remaining patties. Serve on warm buns with Spicy Avocado Yogurt Sauce.