Preparation 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"); 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°F. Using a small serrated knife, make a 1/2"-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.
Preparation 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"); 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°F. Using a small serrated knife, make a 1/2"-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.