Toss raw shrimp with 1 teaspoon of Old Bay seasoning.
Heat a non-stick skillet over medium-high heat and sauté the shrimp for 2 to 3 minutes per side until pink and opaque. Remove from heat and allow to cool completely.
In the same skillet, sauté the corn kernels for 3 to 4 minutes until tender and slightly charred. Remove and let cool.
Once cooled, roughly chop the shrimp into 1/2-inch bite-sized pieces.
In a large mixing bowl, whisk together the mayonnaise, Dijon mustard, lemon juice, remaining 2 teaspoons of Old Bay seasoning, and black pepper.
Fold the chopped shrimp, sautéed corn, diced celery, and green onions into the dressing until evenly combined.
Brush the interior of the mini rolls with melted butter and toast in a clean skillet or under a broiler until golden brown.
Divide the shrimp and corn mixture evenly among the 12 toasted rolls.
Garnish with minced chives and an additional dusting of Old Bay seasoning before serving.