Chicken Tikka Kebab

Name: Chicken Tikka Kebab
Ingredients: ⅓ cup whole milk greek yogurt (plus more for garnish); 2 tablespoons tomato paste; 1 tablespoon extra virgin olive oil; 1 teaspoon fresh grated ginger or ginger paste; 1 teaspoon minced garlic; ½ teaspoon ground turmeric; 2 teaspoons garam masala; ½ teaspoon ground coriander; ½ teaspoon ground cumin; ¼ teaspoon cayenne pepper; 1 ½ teaspoons kosher salt; 2 pounds boneless skinless chicken thighs (cut into 1-inch pieces); 1 large red onion (cut into 1-inch pieces); Lime wedges (or lemon, for garnish); Chopped cilantro (for garnish)