With the rack in the middle position, preheat the oven to 230°C (450°F).
In a bowl, whisk together the vinegar, honey, and mustard. Set aside.
Place the potatoes and carrots on a non-stick baking sheet. Drizzle with the butter and mix well. Season with salt and pepper. Push the vegetables towards the sides of the baking sheet and place the beef roast at the centre.
Drizzle the vinegar mixture over the beef. Insert a meat thermometer in the centre of the roast. Bake for 10 minutes. Reduce the temperature of the oven to 150 °C (300°F). Bake for another 45 minutes or until the thermometer reads 57°C (135°F).
Remove the baking sheet from the oven. Place the roast on a plate and cover with foil. Let rest for 15 minutes. The internal temperature should rise to 145°F (63°C) for medium-rare. Add the peas to the vegetables on the baking sheet and mix well. Turn the oven off. Keep the vegetables warm in the oven while the roast rests.
On a work surface, thinly slice the roast. Place over the vegetables. Sprinkle with parsley.