In a deep pan, heat your oil on a high heat, salt and pepper you chicken breasts and cook on a high heat for 4-5 mins, until slightly browned, but not burned. It will still be raw on the inside. Remove from heat and set aside.

Turn down to medium heat, melt your butter, then add mushrooms, garlic and onion. Cook for 7-10mins, stirring often.

While this is cooking, cut your chicken into bite-sized strips.

Add in your wine and cook for a further 2-3 mins.

Add in your chicken stock and stir well. Add in your sliced chicken. Cover, turn to low heat and cook for 20mins.

Stir through mustard and sour cream, cook for a brief period, until sour cream hot. Adjust salt and pepper levels to taste, and serve over mashed potato or rice.