Tarsis-Style Shrimp

Ingredients

• 4 cups water
• 4 tablespoons fresh lemon juice, plus 2 teaspoons finely grated zest, and spent halves of the lemon reserved
• ¼ cup chopped fresh dill, stems reserved
• Kosher salt
• 2 teaspoons whole black peppercorns
• 2 pounds extra-large shrimp, shelled and deveined
• ⅓ cup mayonnaise
• ¼ cup plain whole-milk Greek yogurt
• 6 scallions, white and green parts thinly sliced and kept separate
• Freshly ground black pepper
• 1 large celery rib, trimmed and finely diced

Instructions

1. In a large saucepan, combine the water, 3 tablespoons of the lemon juice, the spent lemon halves, dill stems, 1 teaspoon salt, the peppercorns, and shrimp. Set the pan over medium-high heat and cook, stirring occasionally, until the shrimp are pink, barely firm, and just cooked through, and the liquid temperature reaches 170°F on an instant-read thermometer, 10 to 15 minutes.
2. While the shrimp poach, set a colander in the sink, and fill a large bowl with ice water and set aside. Drain the poached shrimp in the colander, then, working quickly, transfer them to the ice water, leaving behind the lemon halves, dill stems, and peppercorns. Empty the colander, discarding its contents, and drain the shrimp again. Blot them dry with paper towels, and halve them lengthwise.
3. In a large bowl, combine the mayonnaise, yogurt, scallion whites, chopped dill, lemon zest, remaining 1 tablespoon lemon juice, ½ teaspoon salt, and ½ teaspoon pepper and whisk to incorporate. Add the shrimp and celery and fold to coat with the dressing. Cover and refrigerate so the flavors meld, about 2 hours.
4. Add most of the scallion greens to the shrimp and fold to combine. Adjust the seasoning with additional salt and pepper, if necessary. Sprinkle with the remaining scallion greens before serving.