Marinate: In a mixing bowl, rub the chicken with a pinch of salt and turmeric. Let it sit for 10 minutes.
Temper Spices: Heat mustard oil in a pan until it lightly smokes. Add bay leaf, cinnamon, and cardamom. Let them sizzle.
Sauté Aromatics: Add chopped onions and fry until golden brown. Stir in the ginger and garlic pastes and cook until the raw smell disappears.
Sear Chicken: Add the marinated chicken to the pan. Cook on medium-high heat until the meat turns white and firm.
Add Papaya: Toss in the green papaya cubes and ground spices (cumin, coriander). Stir well to coat everything in the spice mix.
Simmer: Pour in 2 cups of warm water. Cover the pan and simmer on low-medium heat for 20 minutes or until the chicken and papaya are tender.
Finish: Add green chilies, a pinch of sugar, and optional garam masala. Stir once and turn off the heat.