Step 1

Arrange a rack in the middle of the oven and heat the oven to 350°F. Without separating the rolls, cut 1 package Hawaiian sweet dinner rolls in half horizontally with a serrated knife. Place the bottom half of the rolls cut-side up in a 9x13-inch baking dish.

Step 2

Grate 4 ounces cheddar cheese and mozzarella cheese (about 1 cup each). Place both cheeses in a medium bowl and toss to combine. Mince 1 garlic clove.

Step 3

Shred 1 pound cooked chicken into bite-size pieces (about 4 cups). Thinly slice 4 medium scallions (about 1 cup). Place the chicken, scallions, 1/4 cup mayonnaise, 1/4 cup sour cream, 1 tablespoon Dijon mustard, 1/2 teaspoon black pepper, and 1/4 teaspoon kosher salt in a large bowl and stir to combine.

Step 4

Arrange half of the cheese mixture onto the bottom half of the rolls in an even layer. Transfer the chicken mixture over the cheese and spread into an even layer. Top with the remaining cheese mixture.

Step 5

Place 3 tablespoons unsalted butter and the garlic in a small microwave-safe bowl and microwave until melted, about 30 seconds. (Alternatively, melt the butter on the stovetop.) Brush half of the garlic butter on the cut side of the top half of the rolls. Place the top half of the rolls over the sliders cut side down. Brush the tops of the rolls with the remaining garlic butter.

Step 6

Sprinkle with 1 tablespoon white sesame seeds. Cover the baking dish tightly with aluminum foil.

Step 7

Bake until the cheese is melted, 20 to 25 minutes. Uncover and bake until the rolls are lightly browned and toasted, 5 to 7 minutes more. Cut with the serrated knife to separate the sliders into individual sandwiches before serving.