- Preheat oven to 375℉. Have ready a lightly oiled sheet pan.
- Place pork roast in center of sheet pan and sprinkle all over with 1 teaspoon salt and 1 teaspoon pepper. Brush top and sides of roast with mustard, and sprinkle top liberally with sugar, pressing it gently into the mustard so it sticks.
- In a large bowl toss together carrots, parsnips, shallots, oil, thyme, remaining 1 teaspoon salt, and remaining ½ teaspoon pepper. Scatter vegetables around roast.
- Cook until roast is cooked to desired degree of doneness, 60-75 minutes. The internal temperature of the roast should be 135℉ for medium-rare or 150℉ for well-done. If desired, to brown the sugar coating even more, remove the roast from the oven and turn on the broiler. Let broiler preheat for 10 minutes, then place roast back in oven and broil briefly to caramelize sugar topping. Let rest for 10 minutes. During resting the internal temperature will increase by 5-10 degrees.
- Slice the roast to serve.