• Kale, slivered and tossed with olive oil and salt, for garnish
Preheat the oven to 400 degrees. Combine onions, parsnips, carrots and sweet potato in a large roasting pan and drizzle with olive oil. Add the sage, salt and pepper, and toss to coat. Cover the pan tightly with foil, then roast for 25 minutes. Uncover and stir, then cover again for 20 minutes. Let cool. Transfer to a storage container and refrigerate overnight, or proceed.
When the vegetables are cooled, add the parsley and either the pecans or cheese.
Line a sheet pan (preferably one with no rim) with parchment paper. Return the oven to 400 degrees.
Lightly dust counter with flour. Unfold a sheet of puff pastry and use a rolling pin to lightly roll, flattening the fold marks. Place the longer side closest to you, parallel to the edge of the counter. If using the larger Dufour puff pastry, place all the vegetable filling in the middle of the pastry, and fold the long sides up to encase the filling, overlapping slightly and pinching a few times to seal. If using the smaller Pepperidge Farm pastry, make 2 strudels on 2 sheets of pastry. Place seam-side-down on the baking sheet.