Specialty Equipment: (Metal skewers – if you are using wooden skewers soak them in water for about 30 minutes before grilling) 

In a medium bowl stir together the oil, juice of 3 limes, sumac, and 1 ½ teaspoons salt. Add in the cubed chicken breast and toss to coat. Let marinate at room temperature for 20 minutes. 

While the chicken marinades, in a small bowl whisk together the yogurt, grated garlic, grated ginger and ¾ teaspoon kosher salt. Set aside. 

After the chicken marinades, skewer the chicken onto metal or soaked wooden skewers, about 4-5 pieces per skewer. Set aside. 

Preheat a grill or grill pan over medium-high heat. Brush lightly with oil. When the grill is hot add the scallions and tomatoes and grill until the scallions are charred on all sides, about 3-4 minutes and the tomatoes are charred on the bottom and the skin is just beginning to pop, 6-8 minutes. Remove to a serving platter and season with kosher salt to taste. 

Add the chicken skewers to the hot grill and cook about 3 minutes per side, or until the chicken is cooked through and has charred pieces around the edges. Remove from the grill and let rest 4-5 minutes. Serve the chicken with the grilled scallions and tomatoes and the yogurt dipping sauce. Garnish with cilantro or mint if desired.