1. Scrub carrots and beetroot and wash under running water. Peel and cut into batons.
2. Take carrot and beetroot batons in a bowl. Add salt, coarse red chilli powder, coarse mustard powder and mix. Add eighteen cups of water and stir.
3. Cover the bowl with a muslin cloth and tie it round the rim. Let it stand in the sun for three to four days.
4. When ready chill in the refrigerator and serve chilled.