Heat oven to 200C/180C fan/gas 6.
Put 1 tbsp oil in a small roasting tin and
heat up in the oven. Boil the potatoes in
salted water for 3 mins before draining
and letting steam-dry for a few mins.
Season, carefully toss in the hot oil and
cook for 30-35 mins until crisp and golden.
When the chips are nearly done, heat
the rest of the oil in a frying pan. Season
the steak with lots of freshly ground
pepper and a little salt, then fry for
2-3 mins on each side, depending on
how rare you like it. Rest for 5 mins
while you make the sauce.
Pour excess oil from the pan and add
the vinegar. Bubble, then add the stock
and boil until reduced by half. Stir through
the cream, bubbling to thicken a little,
then add as much extra pepper as you
like. Serve with steak, chips and peas.