Put the stock on to heat - in a pan or the microwave
Peel the garlic and crush or finely chop
Season the chicken with salt and pepper
Heat 1 tablespoon oil in a large frying pan on MEDIUM
Add half the butter and when it's melted, add the chicken breasts
Fry for 25-30 minutes, turning occasionally.Larger chicken breasts will need longer The chicken is cooked when the juices run clear when pierced in the thickest part by a sharp knife
Remove the chicken and keep warm in the serving dish
Add the rest of the butter and fry the mushrooms in the pan for about 5 minutes, turning occasionally
Add the garlic and cook for 1-2 minutes
Remove the mushrooms and garlic to a separate dish