Spanish Lentil Soup with Chorizo - Sopa de Lentejas con Chorizo - appears on the menu of virtually every Spanish café or restaurant. It's a peasant dish: really simple to make but extremely tasty.
Finely chop the onion and sauté in some olive oil. Add the minced garlic and chorizo (cut into bite-sized chunks) and cook for a couple of minutes more. When the chorizo has started to release its oil, add the chicken stock and bring it to the boil. Rinse the lentils in cold water and add them to the pan. Peel the potatoes and carrot, cut them into bite-sized chunks and add them to the pan. Turn down the heat to a simmer and put a lid on the pan.
The soup will need to cook for at least 30 minutes, and possibly as much as an hour, depending on the age of your lentils. You're aiming for the lentils to be soft but not disintegrated into a mush.
Serve with crusty baguette and a nice red wine.