Step 1 – Score and Salt the Chicken: Cut 2–3 deep slashes into each chicken leg down to the bone. Rub with 1 teaspoon salt and half the lemon juice. Rest 20 minutes.
Step 2 – Make the Tandoori Marinade: Whisk hung curd smooth, then add ginger garlic paste, mustard oil, lemon juice, tandoori masala, Kashmiri chili, cumin, garam masala, turmeric, and salt into a thick red-orange paste.
Step 3 – Marinate Overnight: Massage marinade into the chicken, cover and refrigerate at least 4 hours, ideally 8–12 hours.
Step 4 – Heat the Oven: Bring chicken to room temp 30–45 min. Preheat oven to 450°F (230°C) with rack in upper third; set wire rack on foil-lined baking sheet.
Step 5 – Roast Hot, Then Char Under the Broiler: Roast 25 min, flipping once. Broil on high 4–6 min per side until edges blacken. Done at 165°F (74°C).
Step 6 – Rest, Baste, and Serve: Rest 5 min. Brush with melted butter, sprinkle kasuri methi, serve with onion rings, lemon, cilantro, mint chutney.