For the Marinade and Tzatziki
2 cups whole milk Greek yogurt
2 tablespoons finely minced garlic (about 4 cloves)
1 tablespoon white wine vinegar
1/2 teaspoon sea salt, plus more to taste
1/4 teaspoon fresh ground black pepper
3 tablespoons extra virgin olive oil
1/2 teaspoon fresh ground cumin
1 tablespoon minced parsley
1 tablespoon minced dill
1 cup grated cucumber (1 medium)
For the Lamb Kabobs
2 pounds boneless American lamb leg meat, cut into 1 1/2-inch pieces
1 large red onion, cut into eighths
The night before or at least 4 hours ahead of time, prepare marinade and tzatziki. Place grated cucumber in a fine mesh sieve over a bowl, set a plate or other heavy object on top, and set in fridge overnight so that cucumber will release its water.
In a medium bowl, stir combine yogurt, garlic, white wine vinegar, sea salt, and pepper. Fold in olive oil. Divide mixture in two. Reserve half for tzatziki, cover, and refrigerate. To the marinade, add ground cumin.
Toss kabob meat with marinade in a zip-top bag and seal. Set in fridge overnight to marinate.
Day of, fold pressed cucumber and herbs into tzatziki. Add sea salt and pepper to taste. Chill until kabobs are ready.
To make kabobs, prepare a hot grill. Allow coals to get hot enough that you can’t hold you hand four inches above them for more than a few seconds. Bank coals to one side of grill to create a zone of high heat and a zone of indirect heat. For a gas grill, turn to medium high 10 – 15 minutes before you plan to grill.
Thread marinated lamb onto skewers alternating with red onion slices. Grill kabobs 2 minutes over high heat, rotate 1/4 turn and grill 2 minutes more; repeat until all sides are grilled. Move kabobs over indirect heat until meat reaches 150°, 4 – 6 minutes more.
Serve kabobs immediately with a generous dollop of tzatziki and grilled flatbreads.