Pre-heat the oven to 200°C, 180°C, gas mark 6. Using a swivel peeler or a mandolin, peel all the vegetables thinly, discarding the outer peel. Spread out the beetroot on a kitchen paper-lined baking tray and the carrot and parsnip on a separate, larger kitchen paper-lined baking tray, and leave for 30 minutes to soak up any excess moisture.
Drizzle 1 tbsp of oil over the carrots and parsnips and 2 tsp of oil over the beetroot and using your hands, toss them so they're evenly coated and are in a single layer. Remove the kitchen paper.
Season lightly with black pepper and roast on the middle shelves 10-12 minutes for beetroot and 15-16 minutes for carrots and parsnips, until they look crispy and shrunken, and the carrots and parsnips are light brown.
Once done, leave to cool slightly on kitchen paper. Serve in some pretty paper cups, and eat immediately.