Marinate the Chicken: In a bowl, combine chicken with yogurt, garlic, ginger, turmeric, cumin, coriander, and salt. Mix well, cover, and marinate for 30 minutes.
Caramelize the Onions: Heat oil in a large pot. Add half of the onions and cook until golden brown. Remove and set aside.
Cook the Chicken: In the same pot, add the marinated chicken and cook until lightly browned. Remove and set aside.
Cook Aromatics: In the same pot, sauté the remaining onions until softened. Add garlic, ginger, and green chilies. Cook for 1-2 minutes.
Simmer the Sauce: Stir in crushed tomatoes and cook for 5-7 minutes. Add chicken and water. Bring to a simmer.
Slow Cook: Cover and simmer on low for 30-40 minutes, until chicken is tender.
Garnish and Serve: Stir in caramelized onions and cilantro. Serve with rice or naan.