Step 1 Season and brown the chicken in a saucepan, heat the butter and oil
Add the chicken and season with salt and pepper
Brown for 3 minutes on each side then remove and set aside.
Step 2 Fry the mushrooms
Add the mushrooms to the same pan and saute until golden.
Step 3 Add the shallots
Cook the shallots while stirring for 1 minute.
Step 4 Add the herbs
Add the garlic, thyme, sage (optional) and cream and stir for another minute.
Step 5 Add the remaining ingredients
Add the mustard and season with salt and pepper.
Stir on a gentle heat for a few minutes until the ingredients are well combined and the cream begins to thicken.
Step 6 Return the chicken to the pan
Put the chicken breasts back in to the pan and cook for a further 2 minutes. Just before serving, pour in the sherry.
Step 7 Garnish and serve
Place chicken on a serving platter, pour over the sauce and sprinkle with parsley to garnish. Serve hot with rice or thickly-sliced brown bread or rice.