Wash the mussels, possibly debone them. Discard opened ones. Peel onions and garlic, dice finely. Fry both in oil in a large saucepan. Add mussels, wine and bay leaf, bring to the boil. Cover and cook for 8-10 minutes, shaking the pot vigorously from time to time.
Scald, quench, skin, seed and dice the tomatoes. Drain the mussels, collect the stock. Bring stock and all tomatoes to the boil, season with salt and pepper. Serve with the mussels. Wash and chop the herbs and sprinkle over the mussels. Baguette tastes good with it.
TIP: Mussels should be closed before cooking or close when you tap them. Throw away closed mussels after cooking!