How to Make It
In a large pot, melt 1 tablespoon of the butter. Add the merguez and cook over moderately high heat, breaking it up with a spoon, until the fat is rendered and the sausage is starting to brown, 3 minutes. Add the shallots and a pinch of salt and cook, stirring occasionally, until softened, 2 minutes. Add the wine, tomato, lime juice, chile and cilantro stems and cook until the wine is slightly reduced, 2 minutes. Stir in the mussels, cover and steam until the mussels open, 7 to 10 minutes; discard any mussels that do not open. Stir in the chopped cilantro and the remaining 1 tablespoon of butter. Ladle the mussels and broth into bowls and serve with crusty bread.
Merguez sausage and Urfa chiles are available at specialty food markets and amazon.com.