Pork tenderloin usually comes vacuum packed in 2 small to medium pieces, weighing about 3-3.5 lbs total. Occasionally, it comes in 1 large piece, especially if purchased from a warehouse store like Costco. The cooking times noted here are for 2 smaller pieces, so adjust accordingly if using 1 large 3-4 lb pork tenderloin. Add at least 10-15 minutes of cooking time for a larg single piece of pork.