Heat the oil in a large saucepan, add the garlic and cook for 30 seconds until starting to sizzle. Add the saffron and wine and bring to the boil, then simmer for a couple of minutes.
Tip in the mussels and tomatoes, cover and cook for about 5 minutes or until the mussels have opened. Discard any that remain closed. Scatter with chopped parsley and serve with plenty of crusty bread.