Preheat the oven to 425 degrees F.
Vegetables: Add all the vegetables, the garlic, olive oil, rosemary salt and pepper, to taste, in single layers on 2 baking sheets. Toss until well coated. Roast until all the vegetables are golden brown and tender, about 45 minutes to 1 hour. Keep warm until serving.
Preheat the oven to 500 degrees F.
Roast: Combine the oil, mustard, garlic, rosemary and pepper in a small bowl. Coat the tenderloin with the mustard mixture. This can be done the day before and left in the refrigerator overnight. Just before roasting, season generously with salt, to taste. Set the tenderloin in a large roasting pan and put it in the center of the oven on the middle rack. Roast until an instant-read meat-thermometer registers 135 degrees F, about 20 minutes. Remove the roast from the oven to a cutting board. Allow it to rest for 10 minutes, tented with aluminum foil. Slice the meat and arrange on a serving platter. Serve alongside the warm roasted vegetables.
You can use any combination of the vegetables or whatever looks good at the market. You want about 1 1/2 cups of vegetables per person.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.