"This dish gets its name from a karahi, a flat open pot used a lot in Pakistani and Indian cooking. In spite of its name, this recipe can be made in any pot. My mom came up with this recipe; it's a little spicy (by Pakistani standards), but simple and foolproof. Serve with naan bread."
Heat oil in a large pot or karahi over high heat. Add chicken pieces and cook until starting to brown, about 5 minutes. Add water, cumin, salt, ginger and garlic paste, red chile powder, and turmeric; cook and stir until fragrant, about 30 seconds.
Stir tomatoes and green chile peppers into the pot. Reduce heat to low, cover, and cook until chicken pieces are no longer pink at the bone, about 30 minutes. An instant-read thermometer inserted near the bone should read 165 degrees F (74 degrees C).
Sprinkle cilantro leaves over the chicken and cook until the leaves look slightly wilted, about 30 seconds.