Plot: Food takes center stage in this tour of the northern Portugal city by Bourdain, whose local travel companions include his former Les Halles boss Jose Meirelles. A sumptuous pig tripe dinner at A Cozinha do Martinho, an at-home meal of sea lamprey and a stop at Café O Afonso for local specialty Francesinha highlight the trip which culminates with a traditional food celebration in the Douro Valley countryside