This long, white root freezes well. Choose young, firm roots.

Scrub but do not peel or cut up. Blanch whole in boiling water for 3 minutes. Drain, then plunge in a bowl of iced water and cool. Drain and dry on kitchen paper, then peel and cut into thick matchsticks.

Pack in convenient quantities in polythene bags. Remove the air, seal, label and freeze. Storage time: 12 months.