Preheat oven to 190°C. Remove roast from fridge and allow to come to room temperature for 25 mins.
Place potatoes on a lined oven tray, toss with 1 tbsp of oil, and season with salt and pepper, set aside until required. Place carrot and onion into a deep roasting pan and toss with another 1 tbsp of the oil.
Pat roast dry with kitchen towel, rub all over with 2 tsp oil and season with a good pinch of salt. Heat a large heavy-based skillet over high heat. Add beef to pan and cook, turning regularly, for 3–4 mins until browned all over. Place seared beef on top of the carrots and onions in the roasting pan.
Roast the beef for 40 mins, then place pan with potatoes into the oven, and continue to roast beef for a further 20–30 mins, or until cooked to your liking.
Transfer beef to a board, cover loosely with foil, and rest for 20 mins before carving. Use a slotted spoon to transfer carrots from the roasting pan to a serving dish, cover to keep warm. Remove potatoes from the oven once golden on the outside, and tender when pierced with a fork.
Tip pan drippings into a saucepan, sprinkle over flour and whisk to a smooth paste. Cook over medium heat for 1 min. Add wine and ½ cup stock, and whisk for another 1 min to cook off the alcohol. Add mustard and remaining 1 cup stock and cook, whisking constantly, for 2–3 mins until gravy has thickened. Whisk in additional stock for a thinner gravy. Stir through parsley and season to taste with salt and pepper.
Serve roast with carrots, potatoes, peas, and gravy.
Approximate cooking temperatures for a roast: Rare, internal temp 55-60ºC. Medium, internal temp 65-70ºC.