Preheat oven to 450°. Line a rimmed baking sheet with foil or parchment paper.
Mix together salt, pepper, brown sugar, garlic powder, and onion powder in a small bowl.
Pat pork tenderloin dry with a paper towel. Rub with Dijon mustard and half of the seasoning mixture. Place in the middle of the baking sheet.
Add vegetables and potatoes in a bowl, add oil and remaining seasoning and toss to combine.
Place vegetables around pork.
Roast pork for 15 minutes, then flip the pork over. Continue to roast until a thermometer registers 145° in the thickest part of the pork, another 10 to 15 minutes.
Cover with foil and let pork rest for 10 minutes before slicing.
While the pork is resting, make the jam sauce. Add oil to a saucepan over medium heat. Add garlic and cook for one minute. Add apricot preserves and cook on low heat until melted. Add vinegar, salt, pepper, thyme, and rosemary. Taste for seasoning.
Serve sauce over pork.