How to Make It
Preheat the oven to 475°. Melt the butter on a large rimmed baking sheet in the oven. Toss the squash in the butter until coated, then lay the wedges on their sides and roast for about 15 minutes, or until browned; turn to the other side and roast for 15 minutes longer.
Turn the squash wedges skin side down and season with salt and pepper. Drizzle with the maple syrup and sprinkle with the coriander. Roast for about 2 minutes, or until bubbling. Remove from the oven, cover loosely with foil and let cool slightly.
Reduce the oven temperature to 375°. Toast the hazelnuts in a pie plate in the oven for 10 minutes, or until browned. Transfer the hazelnuts to a kitchen towel and let cool slightly, then rub the nuts in the towel to remove the skins. Coarsely chop the hazelnuts.
In a medium bowl, combine the hazelnut oil with the vinegar and season with salt and pepper. Add the parsley, ham and toasted hazelnuts and toss well. Arrange 3 squash wedges on each plate, top with the salad and serve.