Preheat the oven to 400 ̊F.

Butterfly Tenderloin: To butterfly the tenderloin, use a sharp knife and make a lengthwise cut down the center of the tenderloin to within 1⁄2 inch of the bottom. Open the cut meat and lay it flat between two pieces of plastic wrap. Pound the meat until it is an even thickness. Remove the top sheet of plastic wrap and lightly salt and pepper the exposed side of the tenderloin.

Mix Stuffing: In a small mixing bowl, stir together the strawberries, garlic, goat cheese, thyme, and pine nuts.

Stuff Tenderloin: Spread this mixture over the top of the tenderloin, leaving a clean 1-inch edge all around. Roll up the long side, removing the plastic wrap. Tie with butcher's twine every 2 inches to secure. Lightly salt and pepper.

Roast Tenderloin: Put the tenderloin in a shallow roasting pan along with the stock. Roast for 12 to 18 minutes, or until the internal temperature reaches 155 ̊F. Remove from the roasting pan, cover loosely with foil, and let the tenderloin rest while preparing the mashed potatoes. Slice and serve alongside potatoes.