1. Preheat oven to 425 degrees F. Spray a large baking dish or rimmed baking sheet with nonstick spray.In a large bowl, combine all the ground chicken with the salt, pepper, egg, panko, garlic cloves, finely diced jalapeño pepper and half (4 ounces) of the grated cheddar.
2. Mix thoroughly to combine, trying not to over mix.
3. Rolls into golf ball-sized meatballs.
4. Bake for 30-35 minutes (the meatballs will release a bit of liquid, as well as some of the cheese), or until meatballs are cooked through.
5. Remove and let cool slightly. Slice each bun lengthwise and stuff some of the remaining cheddar in the bottom of each.
6. Place 2 (or 3, depending on the size of your rolls) meatballs in each bun, then cover with additional cheddar.
7. Place bake in the oven for 6-8 minutes, then broil if desired to bubble and brown the cheese on top. Cover with thinly sliced jalapeños and serve.