1. Heat a large pan over medium heat. Season chicken with salt and pepper and any additional spices you like. Drizzle some olive oil in the pan.
2. When oil is hot, add chicken and cook for five to seven minutes until browned. Flip chicken and cook for another five minutes. Transfer chicken to a plate and set aside, keeping the pan over medium heat.
3. Add onion, garlic, tomatoes, and another pinch of salt and pepper. Cook for three to five minutes, stirring occasionally. Add chicken back into the pan and nestle down into the tomatoes. Cover the pan and reduce heat to simmer. Cook for another five to seven minutes until chicken is cooked through and tomatoes are juicy. Stir in basil leaves and serve.