Wash the mussels well and remove the beards. Discard any that are open, or do not close when sharply tapped. Chop the bacon, onion and celery. Melt the margarine in a pan, add the bacon and onion. Cook for 5 minutes. Stir in the celery, tomatoes, stock and basil. Cook for another 5 minutes. Add the mussels, cover and cook for a further 5 minutes or until all the mussels are open. Shake the pan occasionally. Discard any that do not open. Season with pepper. Either remove the mussels from both shells or serve in the shells. In this case you need small finger bowls ofwater on the table.
Source: Marguerite Patten 's Marvellous Meals, Your Magazine, UK