Heat the oven to 250F. Season the roast on all sides with salt and pepper. Rub just 2-3 tablespoons of the miso (keep the rest of the miso for the Au Jus) on all sides of the roast. Place the roast in a large roasting pan. Scatter the vegetables all around the roast.
Roast until temperature of the middle of the roast is 125 degrees F (medium-rare to medium), which should take about 15-20 minutes per pound, but use a meat thermometer to monitor. The roast will continue to cook to the finished temperature of 135-140 on the counter resting. Turn the broiler to high and let the roast brown a bit on the outside, for about 5 minutes. Transfer roast to cutting board and cover loosely with tin foil. Rest for a full 30 minutes.
While the roast is resting, make the Miso Jus. Keep the vegetables in the roasting pan. Place the roasting pan over 2 burners set on high heat.
Pour in the red wine and cook until wine is reduced by half. Use a wooden spoon to scrape up the bits. Whisk in the broth and 2 tablespoons of miso paste. Turn heat to medium-low and simmer for 15 minutes. Add any juices accumulated from the roast on the cutting board. Turn off heat.
Strain the jus with mesh strainer, pressing down with wooden spoon to extract out all the juice from the vegetables. Carve the roast, serve with the jus.