In a large pot or skillet, heat the vegetable oil over medium heat.
Add the finely chopped onion, minced garlic, and minced ginger. Sauté until the onion is soft and translucent.
Add the bite-sized chicken pieces to the pot and cook until the chicken is browned on all sides.
Stir in the ground cumin, ground coriander, ground turmeric, ground black pepper, and salt. Mix well to coat the chicken evenly with the spices.
Add the chopped tomatoes and green chilies to the pot. Cook for about 5 minutes, stirring occasionally, until the tomatoes begin to break down and form a sauce.
Pour in the water or chicken broth and bring the mixture to a boil.
Reduce the heat to low and let the stew simmer for about 15-20 minutes, or until the chicken is cooked through and the flavors have melded together. Stir occasionally.
Transfer the Jasha Maru to a serving dish.
Garnish with freshly chopped cilantro.
Enjoy your meal!