Preheat the grill, setting the burners to high. Oil the grate.
On a work surface, butterfly the pork tenderloin by slicing the meat lengthwise, without separating it completely. Spread the remaining ingredients lengthwise in the tenderloin. Close and tie with butcher’s twine. Season with salt and pepper. Oil lightly.
Place the tenderloin on the grill. Adjust the burners to medium heat. Grill the meat for about 15 minutes, turning it frequently. Set the meat aside on a plate. Cover with aluminum foil and let rest for 10 minutes.
Divide the cheese and vegetables among plates. Top with the olives, sprinkle with the oregano and drizzle with the olive oil and vinegar. Season with salt and pepper.
Untie the tenderloin. Slice and serve with the salad. Serve with pita bread, if desired.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.