Preheat oven to 180°C Line 2 large, 2cm-deep oven trays with foil.
Using a processor or mandolin, finely shred carrots. Place in a bowl. Add onion, oil, sugar, chilli and nutmeg. Season with salt and pepper. Mix until well combined.
Divide carrot mixture between prepared trays. Roast for 1 hour, swapping trays over in the oven after 30 minutes, or until crisp and golden. Allow to cool slightly. Using tongs, tear carrot mixture into pieces. Serve.