Season the chicken with salt and pepper. Add the oil to a large fry pan over a medium high heat.

Add the chicken to the fry pan and sear on both sides until golden brown, about 2-3 minutes. Remove and set aside.

Add the onion to the pan and cook, stirring occasionally until browned slightly. Add the garlic and mushrooms and cook for 3-4 minutes until mushrooms begin to soften, ensuring you stir to keep from sticking.

When the mushrooms are cooked, add the chicken stock, balsamic vinegar, and thyme to the fry pan. Stir and scrape anything stuck to the fry pan off the bottom, and to coat evenly.

Add the chicken to the fry pan and let simmer for 10-15 minutes on low heat or until chicken is fully cooked. Stir throughout, adding a bit more water if it starts to stick.

Once the liquid in the pan has reduced and the chicken is cooked, stir in fresh parsley and serve.