Combine the marinade ingredients together and add the pork, turning until all sides of the pork are coated. Cover and keep in the fridge for at least one hour but ideally up to three hours.
Preheat the oven to 350˚F.
Place a large skillet over medium-high heat. Remove the pork from the marinade, scraping off any bits of garlic or shallot. Sear on all sides until you have a nice brown color. Set aside.
In a large roasting tin, toss together the vegetable slices and the remaining marinade. The vegetables should be nicely coated in the spiced olive oil. If it seems dry to you, add some more olive oil and toss. Season with salt and pepper.
Place the seared tenderloin on top of the vegetables and transfer to the oven to cook for approximately 25-30 minutes or until a meat thermometer registers 145˚F. Be sure to toss the vegetables two or three times during roasting to ensure they are evenly cooked.