01 - Combine chicken pieces with yogurt, lemon juice, turmeric, and salt in a large bowl. Mix thoroughly to coat evenly. Let marinate for 15 minutes to 2 hours for optimal tenderness.
02 - Heat vegetable oil in a large skillet or Dutch oven over medium heat. Add chopped onions and cook for 5-7 minutes until golden brown and softened.
03 - Add minced ginger, garlic, and chopped jalapeños to the skillet. Sauté for 2-3 minutes until fragrant, stirring constantly to prevent burning.
04 - Stir in diced tomatoes and cook for 4-5 minutes until softened and beginning to break down, forming a base for the sauce.
05 - Sprinkle coriander, cumin, garam masala, cinnamon, chili powder, and black pepper over the mixture. Stir well and cook for 1 minute to toast the spices and release their oils.
06 - Add marinated chicken pieces to the pot. Cook, stirring frequently, for 5 minutes until lightly browned on all sides.
07 - Pour in water or chicken broth, scraping up browned bits from the bottom. Bring to a gentle simmer, cover, and cook for 15-20 minutes until chicken is cooked through and sauce has thickened.
08 - Taste the curry and adjust salt or heat level as desired. Garnish with fresh cilantro and serve hot with steamed rice or naan bread.