Bring a large saucepan of water to a boil. Reduce heat to medium-low; season lightly with salt. When water is at a gentle simmer, add shrimp. Poach until just opaque in the center, 2–4 minutes. Drain; transfer shrimp to a medium bowl of ice water to cool. Drain; wipe out bowl.
Whisk mayonnaise, celery, chives, oil, lemon juice, and horseradish in a medium bowl to blend; season to taste with salt and pepper. Chop shrimp into small pieces (about 1/3-inch); add to bowl with mayonnaise mixture. Stir to coat. DO AHEAD Shrimp salad can be made 1 day ahead. Cover and chill.
Preheat oven to 375°. Using a small serrated knife, make a 1/2-inch-deep cut across the top of each dinner roll and gently pry open roll with your fingers to create a mini New England–style hot dog bun. Lightly brush inside of rolls with butter; place on a rimmed baking sheet. Toast until light golden, about 8 minutes. Let cool slightly.
Divide shrimp mixture among rolls, pressing into cut across top; garnish with celery leaves or crushed potato chips.
Recipe and Picture from www.bonappetit.com/