1. 1. Preheat the oven to 300°F (150°C).

2. 2. Peel the sweet potatoes and butternut squash, then chop into 1-inch (2.5 cm) cubes. Toss on a baking sheet with olive oil, salt and pepper and roast for 45 minutes until tender and caramelized.

3. 3. Melt 1 tablespoon (15 ml) of butter in a large skillet over medium heat. Add the shallots and cook until soft, about 5 minutes.

4. 4. Add the mushrooms and cook until they release their juices and turn golden, around 5 minutes.

5. 5. Add the apple and cook for 1 minute.

6. 6. Pour in the veal stock, heavy cream, Dijon mustard and green peppercorns. Bring to a gentle simmer and let it bubble for 2 minutes.

7. 7. Season the pork tenderloin with salt. Nestle it into the skillet and spoon some of the mushroom mixture over the top.

8. 8. Place the skillet in the oven and let the pork braise for 20 to 25 minutes until it reaches an internal temperature of 145°F (63°C).

9. 9. Remove the skillet from the oven. Stir in the remaining 1 tablespoon (15 ml) of butter and a dash of cornstarch to thicken the sauce.

10. 10. Serve the pork tenderloin with the roasted vegetables, spooning the rich mushroom sauce over the top. Be careful when handling the hot skillet and use oven mitts to prevent burns.