Serves: 4 // Prep time: 30 minutes | Chilling time: 30 minutes to 2 hours | Grilling time: about 8 minutes | Special equipment: grill-proof griddle
2 scallions (white and light green parts only)
1 rib celery, cut into 2-inch pieces
1 pound raw shrimp, peeled and deveined, tails removed
½ cup loosely packed fresh Italian parsley leaves
1 tablespoon Old Bay® Seasoning
1 teaspoon finely grated lemon zest
½ teaspoon mustard powder
¼ teaspoon ground cayenne pepper
¾ cup panko bread crumbs
Extra-virgin olive oil
¼ cup mayonnaise
2 tablespoons dill pickle relish
2 teaspoons prepared horseradish
¾ teaspoon hot pepper sauce
4 hamburger buns, split
4 leaves romaine lettuce
8 very thin slices red onion
8 pepperoncini, thinly sliced into rings (optional)
In a food processor combine the scallions and celery and process until finely chopped. Add the remaining patty ingredients, except the bread crumbs, and pulse briefly until the mixture forms a very chunky mixture, about 8 one-second pulses. There should be many pieces of shrimp remaining, each about the size of a pea. Transfer to a bowl. Add the panko to the shrimp mixture and stir gently until just combined. Form into four patties of equal size, each about 4½ inches in diameter and no more than ½ inch thick.
Lightly coat a platter with oil. Arrange the patties on the platter, cover with plastic wrap, and refrigerate for at least 30 minutes or up to 2 hours.
Combine the sauce ingredients. Refrigerate until ready to use.
Prepare the grill for direct cooking over medium heat (350° to 450°F) and preheat a grill-proof griddle.
Lightly brush the patties on both sides with oil, place on the griddle, and cook over direct medium heat, with the lid closed, until golden and firm, about 8 minutes, carefully turning once after 5 minutes. During the last 30 seconds to 1 minute of grilling time, toast the buns on the cooking grates, cut side down, over direct heat. Build each burger on a bun with sauce, lettuce, a patty, onion, and pepperoncini, if using. Serve warm.