Bread is a staple food prepared by cooking a dough of flour and water and often, additional ingredients. Doughs are usually baked, but in some cuisines breads are steamed, fried, or baked on an unoiled skillet. It may be leavened or unleavened. Salt, fat and leavening agents such as yeast and baking soda are common ingredients, though bread may contain other ingredients, such as milk, egg, sugar, spice, fruit (such as raisins), vegetables (such as onion), nuts (such as walnuts) or seeds (such as poppy). Referred to colloquially as the "staff of life", bread has been prepared for at l...