Combine yogurt, ginger-garlic paste, salt, garam masala, chili powder, turmeric, cumin, and lemon juice. Add chicken thighs and coat completely. Refrigerate at least 1 hour, up to 8 hours.
Caramelize the Onions
Preheat oven to 350°F. Heat oil over medium-high in a large oven-safe cast iron or Dutch oven. Cook sliced onions 12-18 minutes, stirring often, until deep mahogany brown. Remove half for topping.
Brown the Chicken
Add the marinated chicken to the skillet with the remaining onions. Cook for 5-7 minutes, turning once, until the chicken starts to brown and the masala thickens. Turn off the heat.
Parboil the Rice
Rinse rice 3-4 times until water runs mostly clear. Boil 6 cups salted water with whole spices. Add rice and boil 5-6 minutes until 70% cooked (tender outside, firm chalky center). Drain immediately.
Bloom the Saffron (optional)
Steep saffron in 1 tablespoon warm milk for 5 minutes until golden.
Layer
Spread parboiled rice over the chicken. Top with reserved fried onions, cilantro, and mint. Drizzle ghee and saffron milk over the top.
Bake
Cover tightly with foil, then the lid. Bake at 350°F for 40-50 minutes until chicken reaches 175-185°F and rice is fully tender.
Rest and Serve
Rest, covered, for 10 minutes. The fluff gently from the sides with a fork. Serve with raita and lemon wedges.
Notes
The original recipe lists garam masala twice — use 1 teaspoon total.
Marinating overnight (up to 8 hours) gives the deepest flavor and most tender chicken. - Foil plus a tight lid gives better steam seal than lid alone.
Kashmiri chili powder gives color with mild heat; standard chili powder runs hotter.
Refrigerate leftovers up to 3-4 days or freeze up to 2 months. Reheat covered with a splash of water.