Callos

Callos is a stew common across Spain, and is considered traditional to Madrid. In Madrid, it is referred to as "callos a la madrileña.
It contains beef tripe and chickpeas, blood sausage and peppers. Chorizo sausage may also be used. Another simple recipe of callos is boiling the tripe until tender, slicing it into strips and cooking it in pork and beans with peppers. Many people also add cheese to it to really bring out the flavour.