A fragment of mediaeval fireless cooking pot. The technique involved bringing food up to temperature on the fire as usual, but rather than allowing it to cook over the flame, the hot pot was placed in a 'nest' of hay, moss, dry leaves or other insulating material, in a box or hole in the ground, and covered. The heat in the pot was conserved for a considerable length of time, and the food inside would cook slowly, without the need for supervision. Both time and fuel were saved in this way, and foods that needed long slow cooking, such as pulses or tough meat, benefitted from this technique.