In a large bowl, combine ground chicken, breadcrumbs, Parmesan, egg, garlic, onion powder, salt, and pepper.
Mix until well combined, but do not overwork the mixture.
Form the mixture into small patties, about 2 inches in diameter.
Preheat a skillet over medium heat and add a little oil.
Cook the patties for 5-7 minutes on each side, until golden brown and cooked through.
Toast the slider buns lightly in the same skillet.
Assemble the sliders with lettuce, tomato, and a patty.
Add a dollop of mayo on top.
Secure with a toothpick if desired.
Serve immediately and enjoy!