Score the beef. Season with salt and pepper, rub with 20mls of oil. Place potato and pumpkin in a gastronome, drizzle with remaining oil, season with salt and pepper. Gently toss until combined. Place beef on top of vegetables. Roast in oven for 15 minutes to develop a crust. Reduce heat to 160°C and 20% steam. Probe roast and cook to an internal temperature of 56°C for medium rare consistency. Remove from oven, place on a board, cover loosely with foil to rest for half the cooking time.
Thinly carve beef across the grain. Serve with vegetables, Yorkshire puddings and gravy.