Preheat your oven to 200°C (400°F). Prepare a large baking sheet by lining it with parchment paper for easy cleanup.

Prepare the carrots and parsnips. Ensure they are thoroughly peeled to remove any tough outer skin. Trim off the woody ends. Cut the vegetables into uniform pieces, approximately 2.5cm (1 inch) thick. Uniformity in size is crucial for even roasting.

Place the cut carrots and parsnips in a large mixing bowl. Drizzle with 60ml (1/4 cup) of olive oil. Season generously with 5g (1 tsp) of salt and 2g (1/2 tsp) of black pepper. Toss everything together until the vegetables are evenly coated with oil and seasonings. This ensures each piece will roast and caramelize beautifully.

Spread the seasoned vegetables in a single layer on the prepared baking sheet. Avoid overcrowding the pan, as this will cause the vegetables to steam rather than roast. If necessary, use two baking sheets.

Roast the vegetables in the preheated oven for 20-25 minutes. They should be starting to soften and lightly brown at the edges. Give them a toss halfway through the roasting time to ensure even cooking.

While the vegetables are roasting, prepare the maple mustard glaze. In a small bowl, whisk together 60ml (1/4 cup) of maple syrup, 30ml (2 tbsp) of Dijon mustard, and 15ml (1 tbsp) of apple cider vinegar. Whisk until well combined and smooth.

Once the vegetables are tender and lightly roasted (after the initial 20-25 minutes), remove the baking sheet from the oven. Drizzle the prepared maple mustard glaze evenly over the hot vegetables.

Gently toss the vegetables on the baking sheet to ensure they are all coated with the glaze. Return the baking sheet to the oven for another 5-7 minutes. This allows the glaze to caramelize slightly and adhere to the vegetables.

Remove the glazed carrots and parsnips from the oven. Transfer them to a serving dish. Garnish generously with 15g (1/4 cup) of freshly chopped parsley just before serving.