PREHEAT the oven to 450º and line a baking sheet with tinfoil. In a small bowl, whisk together the mustards, honey, orange juice, orange zest, chopped rosemary and brown sugar until smooth, and set aside.
PLACE the tenderloin in the center of the baking sheet and season with salt and pepper. In a medium bowl, toss together the rosemary sprigs, potatoes, green beans and olive oil to coat. Season with salt and pepper, then arrange on the tray around the pork. Drizzle the mustard sauce over the tenderloin and vegetables.
TRANSFER the tray to the oven and cook until the pork reaches an internal temperature of 140º, 20 to 25 minutes. Remove from the oven and let rest for 5 minutes, then carve and serve.