Preheat your oven to 200°C (390°F) and line a large baking sheet with parchment paper. This creates a non-stick surface and makes clean-up easier.
Wash and peel the carrots and parsnips, then chop all root vegetables into uniform 2-3 cm pieces. This ensures even roasting and caramelization.
Trim and halve the Brussels sprouts if they are large. The even size helps them cook uniformly and develop crispy edges.
Place all the chopped vegetables into a mixing bowl. Drizzle with olive oil, then sprinkle with chopped thyme, salt, and pepper. Toss everything together until evenly coated with oil and seasonings.
Spread the vegetables in a single layer on the prepared baking sheet. Make sure not to overcrowd so they roast rather than steam.
Place the baking sheet in the oven and roast for 25-30 minutes, flipping the vegetables halfway through with tongs or a spatula. You’ll see the edges turn golden and caramelized, filling your kitchen with a lovely roasted aroma.
Check for doneness by piercing a vegetable with a skewer or fork; it should slide in easily, and the edges will be nicely browned and crispy.
Once done, remove the vegetables from the oven and transfer to a serving dish. Squeeze fresh lemon juice or sprinkle lemon zest over the top for a bright contrast to the caramelized flavors.
Let the vegetables rest for about 5 minutes to allow flavors to settle before serving. Enjoy their smoky, sweet, and tender goodness as a festive side or part of your holiday feast!
