Heat oil in a large skillet over medium heat. Add onions and cook until softened, about 5 minutes.
Add garlic and ginger, cook for another minute until fragrant.
Add chicken pieces to the skillet and brown on all sides.
Stir in curry powder, cumin, coriander, turmeric, and cayenne pepper. Cook for 1-2 minutes.
Pour in diced tomatoes and chicken broth. Season with salt and pepper.
Bring the mixture to a boil, then reduce heat to low and let it simmer for 20-25 minutes, stirring occasionally.
Taste and adjust seasoning if needed.
Serve the Tomato and Chicken Curry over rice, garnished with fresh cilantro.
Enjoy!