Pour 75ml of wine and 150ml of water to a big pot, put the mussels there, bring everything to boil and cook covered for 4-5 minutes.
Transfer with a slotted spoon the cooked mussels to a bowl and leave till cool enough to handle.
Strain the cooking liquid through a sieve, layered with a cloth to eliminate any sand and impurities.
In the same pot (rinsed) melt the butter, add the chopped onion, leek, carrot, tomato, and garlic; fry for 2 minutes on medium-high heat.
Lower the heat down and fry the vegetables for 3 minutes longer, then add the reserved cooking liquid, the rest of wine (75ml) and of the water (250ml), the chopped parsley and basil and cook for approx. 10 minutes (till carrots are no longer hard).
Remove the mussels from their shells but leave a few for garnish.
Add the mussels, celery, red pepper, cream* and seasoning and serve the soup.