Heat the vegetable oil in a deep, heavy bottomed saucepan until a breadcrumb sizzles and turns brown when added to it. (CAUTION: hot oil can be dangerous, do not leave unattended.)
Rub the beef with the olive oil and season well with salt and freshly ground black pepper.
Heat a griddle pan until smoking. Add the beef and chargrill for 3-4 minutes on each side, or until cooked to your liking. Remove from the heat and rest the beef on a warm plate for one minute.
Meanwhile, carefully add the potato matchsticks to the hot oil and deep-fry until crisp and golden. Carefully remove with a slotted spoon and drain onto kitchen towels. Sprinkle with salt, to taste.
To serve, place the steak onto a warm plate with the fries placed alongside. Drizzle the beef juices from the pan over the steak.