Peter Piper Pickled Prawns

Whisk together vinegar, lemon juice, and 2 teaspoons salt in a large bowl. Gradually whisk in oil.

Bring a large pot of water to a boil. Squeeze in remaining juice from lemons, and drop in rinds. Add shrimp and fennel fronds, reserving some for garnish. Simmer until shrimp are just cooked through, about 3 minutes. Transfer shrimp to a plate using a slotted spoon, and pat dry with paper towels. Add to vinaigrette while still warm; toss. Refrigerate until chilled, about 1 hour.

Toss sliced fennel, red onions, beans, and tarragon with shrimp. Refrigerate for at least 1 hour.

Garnish shrimp with reserved fennel fronds before serving.