This medley of harvest vegetables is simple enough for any day, but is special enough to be a side dish for a Sunday dinner or holiday meal. If you really want to kick it up a notch, crumble 1–2 oz Stilton or other blue-veined cheese over top before serving.
Preheat oven to 400°F.
In a large bowl, toss squash and apples with 1 tablespoon of the oil and half each of the salt and pepper. Arrange on a large rimmed baking sheet lined with parchment paper. Roast, turning once, about 30 minutes, or until browned and tender.
Toss kale with 2 teaspoon of the remaining oil in the same bowl. Push squash and apples to one side of baking sheet. Place kale next to squash and apples. Return to oven and roast 5 minutes, or until wilted.
Meanwhile, heat remaining oil in a large skillet over medium heat. Fry garlic, yellow mustard seed and remaining salt and pepper, stirring, 30 seconds or until garlic is fragrant. Stir in vinegar, honey and Dijon mustard.
Transfer vegetables to serving dish; drizzle with hot mustard mixture and sprinkle with hazelnuts.
Top with toasted pumpkin seeds, sunflower seeds, or sliced almonds instead of hazelnuts, if desired.