Preheat the oven to 425°F (220°C).

Core and chop the apples into ½-inch cubes, slice the carrots diagonally into ¼-inch pieces, dice the onion, and finely chop garlic.

In a mixing bowl, whisk together olive oil, maple syrup, Dijon mustard, salt, black pepper, and thyme.

Add the carrots, apples, and onions to the glaze, and toss until evenly coated.

Spread the glazed vegetables in a single layer on a metal roasting pan.

Roast for 15 minutes, then flip the vegetables and roast for an additional 10-15 minutes until tender and caramelized.