Coat your chicken with salt + pepper.
Pour olive oil into a pan over medium heat and add your chicken and onions. Cook both sides until browned & onions become see through.
Add your can of diced tomatoes. Mix and let cook for 5 minutes.
Add the balsamic vinegar to the pan. Sprinkle some oregano, lower the heat to low, and cook for another 5-7 minutes.
The mixture will become a little thick. Serve over a bed of cous cous & enjoy!