 Complete the following phrase:  Tripas à moda do Porto tripe with white beans is said to have originated in the 14th century, when the Castilians laid siege to Lisbon and blockaded the Tagus entrance. The Portuguese chronicler Fernão Lopes dramatically recounts how starvation spread all over the city. Food prices rose astronomically, and small boys would go to the former wheat market place in search of a few grains on the ground, which they would eagerly put in their mouths when found. Old and sick people, as well as prostitutes, or in short anybody who would not be able to aid in the citys defence, were sent out to the Castilian camp, only to be returned to Lisbon by the invaders. It was at this point that the citizens of Porto decided to organize a supply fleet that managed to slip through the river blockade. Apparently, since all available meat was sent to the capital for a while, Porto residents were limited to tripe and other organs. Others claim that it was only in 1415 that Porto deprived itself of meat to supply the expedition that 