01 - Combine chicken pieces with yogurt, lemon juice, turmeric, and salt in a large bowl. Mix thoroughly to coat all pieces evenly. Let marinate for at least 15 minutes, or up to 2 hours in the refrigerator for enhanced flavor penetration.
02 - Heat vegetable oil in a large skillet or Dutch oven over medium heat. Add finely chopped onions and sauté for 5 to 7 minutes, stirring occasionally, until golden brown and softened.
03 - Add minced ginger, garlic, and chopped jalapeños to the skillet. Cook for 2 to 3 minutes, stirring constantly, until fragrant and raw garlic aroma dissipates.
04 - Stir in diced tomatoes and cook for 4 to 5 minutes until softened and beginning to break down, forming a base for the sauce.
05 - Sprinkle ground coriander, cumin, garam masala, cinnamon, chili powder, and black pepper over the mixture. Stir well to combine and cook for 1 minute to toast the spices and release their essential oils.
06 - Add marinated chicken pieces to the skillet. Cook, stirring frequently, for approximately 5 minutes until chicken is lightly browned on all sides.
07 - Pour in water or chicken broth, scraping up any browned bits from the bottom of the pan. Bring to a gentle simmer, cover, and cook for 15 to 20 minutes until chicken is cooked through and sauce has thickened to desired consistency.
08 - Taste the curry and adjust salt or heat level as needed. Remove from heat, garnish with chopped fresh cilantro, and serve immediately.