Here is the full recipe as found in the Tavern on the Green cookbook - offered as an appetizer, but we use as the main dish.
Spicy Lamb Meatballs with Tzatziki
Tzatziki is a typical Greek condiment made with yogurt, garlic, and cucumbers. It is always served cool, often with grilled meats. Use a light hand when forming the meatballs: A gentle touch ensures that the meat will not be compacted or overheated by contact with your hands, and that the resulting mouthfuls will be light and tender. You can cook and cool the meatballs, refrigerate them for up to four hours, and then reheat in a 350 degree F oven until heated through (ten to twenty minutes). However, they will not be as light as meatballs served immediately after cooking.
To lend a bit of drama to the presentation, spike each meatball with a long skewer rather than the expected toothpick. Serves 10-12: May be halved or doubled.
2 tablespoons olive oil
1 small yellow onion, very finely chopped
1 pound grass-finished ground lamb
2 large eggs, lightly beaten
½ cup flat-leaf parsley leaves, chopped fine
2 tablespoons fine, dried bread crumbs
1 ¼ teaspoons ground cumin
4 large garlic cloves, very finely chopped or pushed through a press
Salt and freshly ground black pepper
1 ½ cups plain Greek-style yogurt (such as Fage)
½ English cucumber, peeled, seeded, and finely grated
One and a half to 4 1/2 hours before serving time: In a frying pan over medium-low heat, warm the oil. Add the onion and cook, stirring occasionally, until very soft, about 6 minutes. Let it cool about 5 minutes. Transfer to a large bowl and add the lamb, eggs, parsley, bread crumbs, cumin, three quarters of the garlic, 1 teaspoon salt, and 1/2 teaspoon pepper.
Using your hands, combine the ingredients and form the mixture into golfball-size balls, rolling them lightly between your palms. Place on a lightly oiled rimmed baking sheet. Refrigerate for at least 1 hour and up to 4 hours.
Remove the meatballs from the fridge and preheat the broiler to high; place an oven rack about 4 inches below the heat source. Broil the meatballs, turning once with tongs, until brown and crispy, 10 to 15 minutes.
Meanwhile, make the tzatziki: In a medium bowl, whisk together the yogurt, cucumber, the remaining garlic, and 1/2 teaspooon salt. Taste for seasoning and add more salt, if desired. Skewer each meatball and place on a platter. Place a bowl of tzatziki in the center and transfer the platter to a buffet, or pass at once.