Wash the mussels in cold water. Remove the beard, if present. Sort out opened and damaged mussels.
Heat the oil in a very large wide pot. Brown the onions, garlic, carrots and fennel for 2-3 minutes. Season with pepper and a little salt. Pour wine and 1/4 l water, bring to the boil and stir in broth.
Add the mussels and cook in a closed pot at high heat for about 10 minutes. Shake the pot from time to time.
Drain the mussels, catch the stock and mix with cream, season to taste. Discard closed mussels. Arrange mussels with vegetables and stock. Cut baguette into slices and add.