Most yams keep well and were often used as provisions for lengthy sea voyages. Steaming, or boiling and mashing (or boiling and then grilling), or roasting, or frying (including fried croquettes of mashed yam) are recommended ways of cooking them. See also foo-foo.
Lovelock (1972) describes some unusual practices. In Fiji, the yam is ‘grown in earth that is hard and unprepared in the belief that it is a sporting sort of vegetable that likes to feel resistance before it will show its strength (and therefore grow large)’. He continues:
In the D’Entrecasteaux Islands, off the east coast of New Guinea, there lives a gloomy and suspicious people who believe that yams travel underground from garden to garden. They therefore spend a good deal of time trying to entice their neighbours’ yams into their own plots by magic; and yet are righteously indignant if someone else’s superior magic (or husbandry) produces a crop better than their own. In the neighbouring Trobriand Islands there is a much happier and more open race. These make a parade of their wealth by constructing fairly open yam-houses in order that all can see the quality of their produce, putting roots of best quality well to the fore, of course. Particularly fine yams, however, are displayed outside the stores, often framed and decorated with paint.