Heat the vegetable oil in a large skillet over medium heat. Add the cumin seeds and let them sizzle for about 30 seconds until fragrant.
Add the chopped onions and sauté until they turn golden brown, about 5-7 minutes.
Stir in the minced garlic and grated ginger, cooking for an additional 1-2 minutes until aromatic.
Add the diced tomatoes and tomato paste, cooking until the tomatoes break down and the mixture thickens, about 5 minutes.
Sprinkle in the coriander powder, turmeric powder, garam masala, red chili powder, and salt. Stir well to combine all the spices with the tomato mixture.
Add the chicken pieces to the skillet, stirring to coat them in the spice mixture. Cook for about 5 minutes, allowing the chicken to brown slightly.
Pour in the water, bring to a simmer, and cover the skillet. Reduce the heat to low and let it cook for 20-25 minutes, stirring occasionally, until the chicken is cooked through and tender.
Taste and adjust seasoning if necessary. If you prefer a thicker sauce, uncover and cook for an additional 5-10 minutes.
Garnish with fresh cilantro before serving.