How to Make It
Place first 9 ingredients in a large bowl; toss to coat. Squeeze lemon wedges over lamb mixture, and add rinds to mixture; toss to combine. Let stand 1 hour. Soak 12 (6-inch) wooden skewers in cold water for 30 minutes.
Thread 3 lamb cubes and 2 tomatoes onto each skewer, alternating lamb and tomato. Discard marinade.
Heat a large cast iron skillet or grill pan over medium-high heat; coat pan with cooking spray. Place 6 skewers in skillet. Cook 4 minutes on each side or until desired degree of doneness. Remove skewers to a platter. Wipe skillet clean with paper towels. Repeat with cooking spray and remaining skewers. Serve with Tzatziki.