Lemony Grilled Chicken Kebabs

Ingredients

1. 1 medium onion, coarsely chopped
2. 2 tablespoons fresh lemon juice
3. 1 tablespoon kosher salt
4. 1/2 teaspoon ground black pepper
5. 1 1/2 pounds skinless, boneless chicken thighs
6. Ground sumac, for dusting (see Note)
7. Tahini, for serving

1. In a blender or food processor, puree the onion with the lemon juice, salt and pepper. In a large, shallow glass or ceramic dish, coat the chicken thighs with the marinade. Cover with plastic wrap and refrigerate for at least 3 hours and up to 12.
2. Light a grill. Remove the chicken thighs from the marinade and pat dry with paper towels. Thread the chicken thighs onto four 10-inch metal skewers. Grill over moderately high heat, turning once, until lightly charred and cooked through, about 8 minutes. Lightly dust each skewer with ground sumac. Serve right away, with tahini for dipping alongside.