Bring a medium pot of water to a boil over high. Add shrimp; remove from heat. Cover; let stand until shrimp are cooked through, 2 to 3 minutes. Drain; let stand at room temperature until cooled, 10 minutes. Peel and roughly chop.

Stir together next 6 ingredients and 1 teaspoon of the chives in a medium bowl. Add shrimp; toss to combine.

Melt 1 tablespoon butter in a large nonstick skillet over medium. Place 6 rolls in skillet, top sides down, gently pulling rolls open so insides of rolls toast, about 1 minute. Remove rolls from skillet; set aside. Repeat with remaining 1 tablespoon butter and 6 rolls.

Fill each roll with 2 tablespoons shrimp mixture. Sprinkle with remaining 1 teaspoon chives and celery leaves; serve immediately.