Pyrenean Potato and Kale Cake

I love this quintessential winter dish of Cerdanya, a section of the Catalan Pyrenees where Barcelonans escape to breathe mountain air, pick wild mushrooms, or just lose themselves rambling on the back roads among wild goats and ram-shackle Romanesque churches. There, trinxat is prepared with potatoes and col de invierno, a local variety of winter cabbage. With its curly dark leaves, col de invierno is actually closer to our kale. Josep Maria Boix, a renowned local chef