In a medium bowl, whisk together Greek yogurt, extra virgin olive oil, grated garlic, lemon zest, lemon juice, and Kosher salt. Set aside.
Preheat a grill with the lid down over medium-high heat. Place the salmon into a large mixing bowl. Drizzle with neutral oil, then season with za’atar, Kosher salt, sumac, and black pepper. Toss to evenly coat.
If using metal skewers, simply alternate pieces of seasoned salmon cubes with folded over slices of lemon. We recommend salmon per skewer. If using wooden or bamboo skewers, soak in water for 1 hour first, then assemble the skewers.
When the grill is hot, lightly grease the grates with oil or grill spray. Carefully place the skewers down, then cook on the first side, or until the salmon easily pulls away from the grates. Flip the skewers over, and cook. Remove from the grill and serve.