Over medium-high heat, heat a large saucepan or pot or Dutch oven. Add the chorizo and cook, stirring occasionally, until lightly browned, about 2 to 3 minutes. Stir in the onion and garlic and cook 1 minute. Add the potato wedges, clam juice and water. Bring to boiling, cover and cook 8 minutes or until potatoes are almost tender. Add mussels, cover, return to a boil and cook until the mussels open, about 3 to 4 minutes. Discard any mussels that do not open. Stir in cilantro.