Dwarf bread is rock-hard (and indeed contains various rocks such as gravel), never goes stale, and is terribly sustaining. A traveller can go for miles, just knowing there's dwarf bread in their pack. A traveller can think of just about anything to eat rather than dwarf bread, including their own foot.
Various forms of dwarf bread can be used as weapons, e.g. battle muffins and drop scones.
Proper dwarf bread has to be not just baked, but forged and dropped in rivers and dried out, and sat on and left, and looked at every day and then put away again. For preference, its use as a cat's litter box is also recommended.
Dwarfs generally devour it with their eyes, because even dwarfs have trouble with devouring it any other way.

(from various Discworld novels)