Season the steaks on both sides with salt and pepper.
Heat the butter and oil together in a large frying pan and as soon as the butter stops foaming add the chops. Cook over a medium heat for 3–4 minutes each side until golden. Remove from the pan and wrap loosely in foil. Rest for 5 minutes.
Add the stock to the pan and simmer for 3 minutes then stir in the cream and mustard and simmer gently for 1–2 minutes until thickened slightly. Add the tarragon and remove from the heat.
Arrange the pork on plates, pour over the sauce and serve with some steamed green vegetables, if liked.