Preheat oven to 425°F / 220°C . Line a large rimmed sheet pan with parchment for easy cleanup.
Cut vegetables into even, bite-sized pieces (about 3/4–1 inch / 2–2.5 cm) for uniform roasting.
Season: In a large bowl, combine carrots, sweet potatoes, beets, and red onion. Add olive oil, thyme, garlic powder, salt, and pepper. Toss until every piece is lightly coated.
Roast: Spread in a single layer on the sheet pan—avoid crowding (use two pans if needed).
Bake 25–30 minutes, stirring once halfway, until edges are caramelized and centers are tender when pierced with a fork.
Taste & Adjust salt and pepper. Garnish with parsley. Serve hot. Make It Crispy: For extra color, roast the final 3–5 minutes on the top rack .