Al, either soak some beans (something like borlotti or flageolet) or get a few tins of said beans and simply drain them. Chop up some of your chorizo and fry it off with some chopped onion and garlic. Add some fresh thyme and the beans. Give a few stirs, cover with water or stock and simmer on a low heat, stirring occasionally. Give it at least an hour (tinned beans don't take so long). You could give the soup a bit of a bash with a hand potato masher towards the end to get the beans to break down a bit and the soup to thicken. either add more liquid or reduce, depending on how thick you want it.