Heat about 2 teaspoons of oil in a nonstick skillet over medium heat. Add onion and saute for 2-4 minutes. Add garlic and saute for another 2 minutes, until fragrant, but not browned. Remove from heat, transfer to a large bowl, and let cool.
Add the ground turkey, 1 tablespoon olive oil, parsley, salt, and pepper, to the bowl with the cooled onion and garlic mixture. Mix everything with a wooden spoon or your hands until well combined.
Form mixture into 8 sliders and place onto a cutting board or sheet pan covered with parchment paper for easy cleanup.
If grilling, oil grates, or indoor grill pan, with about 2 teaspoons of oil first. Then heat grill and when hot cook for 3-4 minutes per side, or until cooked through. If cooking in a pan, heat nonstick pan over medium heat, add about 2 teaspoons of oil and cook for 3-4 minutes per side, or until cooked through.