Heat the oven to 425°F and line a large rimmed sheet pan with parchment paper.
Toss the carrots with 1 1/2 tablespoons olive oil, 1/2 teaspoon salt and 1/4 teaspoon black pepper and roast for 12 minutes.
Coat the pork with the Dijon and remaining olive oil, salt and black pepper.
Turn the carrots, then add the pork and pear quarters to the pan in one layer.
Roast for 18 to 23 minutes more, until the pears brown and the thickest part of each tenderloin reaches 145°F.
Rest the pork for 5 minutes before slicing it across the grain.