Heat the oil in a karahi (wok) or heavy, deep skillet over high heat. Add the chicken pieces and sear for 4–5 minutes, turning, until lightly golden on the edges. Push the chicken to the sides of the wok.

Reduce heat to medium-high. Add the ginger garlic paste to the center and sizzle for 30 seconds until fragrant. Stir in the chopped tomatoes, salt, red chili powder, turmeric, crushed coriander seeds, and black pepper. Mix everything together well.

Cover and cook for 8–10 minutes, stirring once or twice, until the tomatoes soften and collapse. Then uncover, raise the heat, and cook another 5–7 minutes, stirring, until the gravy thickens and the oil (or ghee) starts to separate and glisten at the edges — that's the "masala bhun gaya" sign your karahi is ready. If using garam masala, stir it in now. The chicken should be cooked through (165°F / 74°C internal temperature); if using bone-in pieces and the gravy thickens before the chicken is tender, add ¼ cup water and simmer a few more minutes.

Lower the heat. Stir in the 2 tablespoons of ghee, the slit green chilies, and half of the ginger juliennes. Simmer for 2 minutes so the chilies soften slightly and the ghee melts into the gravy.

Turn off the heat. Scatter the remaining ginger juliennes and fresh cilantro over the top and serve immediately, straight from the karahi if you like — the traditional dhaba way — with hot naan.