Chicken Tikka Kebabs

Name: Chicken Tikka Kebabs
Ingredients: 3 cups roughly chopped fresh mint (about 3 ½ ounces, or 2 large bunches); ½ cup roughly chopped red onion (from 1 small [7-ounce] onion); ¼ cup water, plus more as needed; 1 tablespoon coarsely chopped (seeded, if desired) fresh Indian or Thai green chiles (from 4 medium [about 1/2 ounce total] chiles; 2 teaspoons coarsely chopped peeled fresh ginger; 6 cups roughly chopped fresh cilantro (7 ounces, or 5 medium bunches), divided; 1 tablespoon plus 1 teaspoon fresh lemon juice (from 1 medium lemon); 1 teaspoon kosher salt; 1 teaspoon granulated sugar; 5 pounds boneless, skinless chicken thighs, each cut into 3 or 4 pieces depending on size of thighs; ⅓ cup fresh lemon juice (from 2 large lemons); ¼ cup ginger-garlic paste (from 1 [7-ounce] jar), divided; ¼ cup Kashmiri red chili powder (such as Deggi Mirch), divided; 2 teaspoons kosher salt, divided; 3 tablespoons mustard oil; 1 ½ tablespoons garam masala; 2 teaspoons ground turmeric; 2 cups plain whole-milk strained yogurt (such as Greek-style yogurt); 6 tablespoons (3 ounces) salted butter, melted; 2 tablespoons chaat masala