Preheat oven to 200°C (180°C fan).
Toss sweet potatoes, Brussels sprouts, and carrots with olive oil, maple syrup, paprika, salt, and pepper.
Spread evenly on a large baking tray.
Roast for 35–40 minutes, turning halfway through, until caramelized and tender.
While the vegetables roast, melt butter in a small pan.
Add walnuts, maple syrup, and salt.
Cook for 2–3 minutes until glossy and lightly caramelized.
Transfer roasted vegetables to a serving dish.
Sprinkle feta evenly over the top.
Scatter candied walnuts over the vegetables.
Finish with fresh herbs, orange zest, or chili flakes if using.