Step 1

Arrange a rack in the middle of the oven and heat the oven to 425°F. Lightly coat a rimmed baking sheet with olive oil.

Step 2

If any of the 1 1/2 pounds baby potatoes are larger than 1-inch, cut in half. Place the potatoes, 1 tablespoon of the olive oil, and 1/2 teaspoon of the kosher salt in a large bowl and toss to combine.

Step 3

Place 1 tablespoon Dijon mustard and 1 tablespoon honey in a small bowl and stir to combine. Season 1 pork tenderloin with 1/2 teaspoon of the kosher salt and 1/4 teaspoon black pepper. Brush the pork with half of the honey mustard mixture. Place the pork in the center of the baking sheet. Arrange the potatoes cut side down around the pork (reserve the bowl).

Step 4

Roast for 10 minutes. Meanwhile, trim the stem ends from 12 ounces green beans. Place the green beans, remaining 1 tablespoon olive oil, and remaining 1/4 teaspoon kosher salt in the reserved bowl and toss to combine.

Step 5

Flip the pork, then brush with the remaining honey mustard. Arrange the green beans among the pork and potatoes. Roast until an instant-read thermometer inserted into the center of the pork registers at least 145°F and the vegetables are tender, 10 to 15 minutes more. Transfer the pork tenderloin to a clean cutting board, cover loosely with aluminum foil, and let rest for 10 minutes. Slice crosswise and serve with the potatoes and green beans.