Thomasina Myers’ Mexican chain, Wahaca, have kicked off their weeklong celebration of Dia de los Muertos – the Mexican Day of the Dead. An insistent ‘celebration of life’, a slogan that adorns the walls, the custom menus, and the memory wall on which you can commemorate your loved ones, this is by no means a morbid event – and we went along to check it out. To mark this Mexican festival, Wahaca have not just hung bright banners and customised…