- Heat the wine in a saucepan, add the mussels in three batches, cover pan and cook for a few minutes, removing mussels as they open. Reserve the liquid and boil to reduce to ½ cup.
- Remove the top shell from each of the mussels and arrange the shells containing the mussel meat in a heatproof dish.
- To make the sauce, heat a saucepan, add the oil and onion, then cook for 10 minutes until softened. Add the garlic and cook for 30 seconds more. Stir in the flour, then add the reduced wine stock and blend to form a smooth sauce.
- Add tomato paste, spices and lemon juice pf a lemon and simmer for a few minutes to form a thick sauce. Season with salt and pepper to taste. Pour sauce over mussels to serve.