Preheat the oven to 400°F (200°C). Line a large baking sheet with parchment paper.
Cut the vegetables into similar-sized pieces so they cook as evenly as possible.
In a small bowl, whisk together the maple syrup, Dijon mustard, and olive oil until smooth.
Place the vegetables in a large mixing bowl. Pour the maple Dijon mixture over them and toss thoroughly until every piece is lightly coated.
Season with salt and freshly ground black pepper.
Arrange the vegetables across the prepared baking sheet in a single layer. Leave some room between the pieces to encourage browning rather than steaming.
Roast the Maple Dijon Roasted Vegetables for 25–30 minutes, turning them once about halfway through cooking.
Remove them from the oven when the vegetables are tender inside with caramelized, golden-brown edges.
Serve warm as a side dish or spoon over cooked rice, quinoa, or another favorite grain for a simple meal.