Place the ground lamb in a medium bowl and break it apart with a fork. Add onion and garlic and mix thoroughly with your hands. Add remaining ingredients and mix, again with your hands, until the seasonings are evenly distributed throughout the meat.
Preheat oven to 425F and line a large baking sheet with parchment paper. Using a dessert spoon or an ice cream scoop, take up about 1 1/2 tablespoons of the lamb mixture, roll it into a ball and place on the prepared baking pan. Repeat with the remaining mixture. (You should get between 24 and 30 meatballs.)
Bake for 12 to 15 minutes, until meatballs are browned and sizzling. Remove from oven and keep warm under a tinfoil tent until ready to serve.