In a small bowl, stir together the milk, breadcrumbs, garlic, and onion. Let it sit for 2-3 minutes so the breadcrumbs absorb the milk.
In a large bowl, add the ground turkey, egg, Parmesan, parsley, salt, and pepper. Add the milk-breadcrumb mixture. Gently mix everything until just combined; don’t overmix.
Lightly grease your hands and roll the mixture into balls (about golf ball size).
Add oil to a large nonstick or cast iron skillet. Heat over medium until the oil shimmers.
Place the meatballs in the skillet in a single layer, leaving space between them. Cook for 10-12 minutes, turning every 2-3 minutes to brown all sides evenly.The meatballs are done when they’re golden brown on the outside and reach an internal temperature of 165°F. Serve warm with your favorite sauce, pasta, or side dish.