Place a rack in the center of your oven and preheat your oven to 375°F. Line a rimmed baking sheet with parchment paper.
In a large bowl, place the lamb, red onion, panko, egg, lemon zest (zest the lemon directly into the bowl), salt, cumin, coriander, garlic powder, and black pepper. Sprinkle the cilantro over the top.
With your hands, gently combine all of the ingredients until well mixed. Be careful not to overwork the meat or your meatballs will be tough.
Shape the mixture into meatballs that are about 1 1/2-inches in diameter; you'll have about 18 meatballs total. Arrange them on the prepared baking sheet so they are not touching.
Bake lamb meatballs until browned on the outside and cooked through, about 20 to 25 minutes. An instant-read thermometer should register 160°F when inserted in the center of a meatball. Serve warm with tzatziki, hummus, and pita as desired.
Notes
TO STORE. Transfer the lamb meatballs to an airtight container and store them in the refrigerator for up to 3 days.
TO REHEAT. Place the meatballs on a baking sheet and cover them with aluminum foil. Bake in a 350ºF until warmed through.
TO FREEZE. Arrange the lamb meatballs on a parchment-lined baking sheet and freeze until solid, or for about an hour. Once frozen through, transfer them to a freezer-safe bag or container and store in the freezer for up to 3 months. Thaw before reheating.