Spanish chorizo is made with cured or semi-cured chopped pork (usually smoked) and seasoned predominantly with smoky Spanish paprika. In Spain, every region has its own style of chorizo (called chouriço in Portugal)—softer or drier, spicier or sweeter, long and thin or short and fat. In the United States, it is generally a thin sausage that has been air-dried to a hard consistency. It is sold in the cured meats section of specialty foods stores and some supermarkets. It can be sliced for a sandwich or chopped and added to a dish. The closest substitute for Spanish chorizo is probably Portuguese linguiça, also a smoked, cured hard sausage.
Because chorizo comes in both fresh and dry forms, it’s important to check the recipe to make sure which type of chorizo is called for