Preheat the oven to 400°F and line a sheet pan with parchment.

Gently mix the turkey, feta, grated onion, minced garlic, egg, oregano, half the dill, 0.5 teaspoon salt, and the pepper — stop as soon as it's combined.

Roll into 20 meatballs, about 2 tablespoons each. Wet hands keep the mixture from sticking.

Bake 18 to 20 minutes, until the centers reach 165°F.

While they bake, stir the Greek yogurt, lemon juice, grated garlic, remaining dill, and remaining salt into a sauce.

Serve the meatballs over rice, in pitas, or on a pile of greens, with the sauce for dipping or drizzling.