Melt the butter in a saucepan over medium heat. Add onions, carrots and fennel, thyme, parsley and bay, and sauté until lightly browned. Stir in the tomato paste, then add the wine and vermouth. Simmer until reduced by ½. Add the fish stock and simmer 15 minutes. While the stock is simmering, puree the cooked rice or pass it through a food mill. After the fish stock et al is done simmering, strain it into another saucepot containing the cooked rice. Heat the cream separately and add it to the soup mixture. Add the crab meat and season to taste. Garnish each bowl with a parsley or thyme sprig.