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. Mix thoroughly to combine, trying not to over mix. Rolls into golf ball-sized meatballs. 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. Remove and let cool slightly.