Prepare the Spinach:

Blanch the spinach in boiling water for 2-3 minutes, then transfer to ice-cold water to retain its green color. Drain and puree the spinach in a blender. Set aside.

Cook the Chicken:

Heat oil or ghee in a large pan over medium heat. Add onions and sauté until they turn golden brown.
Stir in the ginger-garlic paste and cook until the raw smell disappears.
Add the chicken pieces and brown them on all sides.
Mix in garam masala, turmeric, coriander, cumin, red chili powder, and salt. Cook for a few minutes until the spices are well incorporated with the chicken.

Combine Chicken and Spinach:

Add the pureed spinach to the chicken. Stir well to combine.
Pour in water or chicken broth to achieve the desired consistency. Bring to a boil, then reduce the heat and simmer for 20-30 minutes, or until the chicken is tender and the flavors meld.

Final Touches:

If using, stir in yogurt or cream for a richer, creamier gravy. Adjust the seasoning if necessary.

Garnish and Serve:

Garnish with fresh cilantro leaves. Serve hot with steamed rice, naan, or roti.