Toss diced butternut squash, apple, onion and fresh sage with seasoning and olive oil. Spread in single layer on a shallow baking sheet. Roast for 20-25 minutes, until squash is tender.
Meanwhile, butterfly turkey tenderloins and pound to even thickness, about 3/4-inch. Reserve.
Cut 6 pieces of 12-inch butcher's twine for each tenderloin. Lay butterflied tenderloin on top of strings. Portion out 2 cups of veggie filling and split between each tenderloin. Tie snuggly with twine. Add remainder of olive oil to skillet and brown tenderloins on all sides.
Transfer tenderloins to oven and bake for 30 minutes. 165 degrees is the recommended temperature. Rest 5 - 10 minutes before slicing.