Add the oil to the pan and fry the chicken breasts until cooked through then take out. Slice into small chunks. Next, add bacon and cook until crispy.
Add the onions and continue frying until golden and soft. Add the mushrooms, cook until all the moisture has gone.
Add the butter and fry the garlic, then deglaze with brandy.
Pour in the chicken stock and reduce until thick. Add cream and reintroduce chicken to the mixture.
Put pastry lid on top and cut a cross for the steam to escape. Brush with egg yolk. Bake for 40 minutes until risen and delicious looking.