How to Make It
In a large nonreactive saucepan, warm the olive oil over moderate heat. Add the onion and cook, stirring, until translucent, about 5 minutes. Add the chorizo and cook, stirring, until heated through, about 1 minute. Add the potatoes, paprika and 1 tablespoon of kosher salt; stir well. Add 4 cups of water and bring to a boil over high heat. Reduce the heat to low, partially cover and simmer, stirring occasionally, until the potatoes are tender when pierced and the stew has thickened slightly, about 30 minutes.
Uncover the stew, increase the heat to high and bring to a boil, stirring occasionally, to incorporate the oil on the surface into the stew. If desired, crush some of the potatoes against the side of the pan to thicken the stew. Season with kosher salt if necessary. Ladle the stew into shallow soup bowls and serve at once.