In a mixing bowl, combine the ground turkey, breadcrumbs, Parmesan cheese, minced garlic, onion powder, oregano, salt, and black pepper. Mix until just combined; do not overwork the meat.
Divide the mixture into 4 equal portions and shape them into small patties about 1/2 inch thick.
Preheat your grill or skillet over medium-high heat. Lightly oil the grill grates or skillet to prevent sticking.
Grill the turkey patties for about 6-7 minutes on each side or until they reach an internal temperature of 165°F (75°C).
During the last minute of cooking, you can add cheese slices on top of the patties if desired and cover to melt.
Remove the patties from the heat and let them rest for a couple of minutes. Meanwhile, lightly toast the slider buns on the grill or in a toaster.
Assemble the sliders by placing a turkey patty on each bun and topping with lettuce, tomato slices, and any condiments of your choice.
Serve immediately and enjoy!