Put a large skillet over medium-high heat and add the oil. When it starts to get hot, add the onion, garlic, and ginger and cook for 4 minutes, or until the onion is golden. Add the tomato paste, brown sugar, cumin seeds, garam masala, red chile flakes, turmeric, and salt and cook for 2 minutes. Add the chicken cubes and stir well to coat. Add the yogurt and water and cook, stirring until the chicken is done, about 8 minutes. Serve the chicken with roti or rice.