Heat the vegetable oil in a large skillet over medium heat. Add the cumin seeds and sauté for about 30 seconds until fragrant.
Add the chopped onion and cook until golden brown, about 8-10 minutes. Stir occasionally to prevent burning.
Stir in the minced garlic, grated ginger, and green chilies. Sauté for another 2-3 minutes until fragrant.
Add the coriander powder, turmeric powder, garam masala, and red chili powder. Cook for 1-2 minutes, stirring constantly to toast the spices.
Add the chicken pieces to the skillet, stirring well to coat them with the spice mixture. Cook for about 5-7 minutes until the chicken is browned on all sides.
Pour in the drained diced tomatoes and chicken broth. Stir to combine, then bring to a simmer.
Reduce the heat to low, cover, and let it cook for 25-30 minutes, stirring occasionally, until the chicken is cooked through and tender.
Season with salt to taste and garnish with fresh cilantro before serving.