Making the sauce: Sauté the
lobster heads in a little
olive oil. Deglaze with cognac; flambé and reduce until the liquid has evaporated. Add the white
wine and reduce again. Add the chopped fresh tomatoes,
garlic,
fennel and
onion (
all coarsely chopped) and the herbs.
Cook over medium heat until the water they exude has evaporated. Add the
fish stock and
cook over low heat for 1 and a half hours. Let infuse for about 30 minutes off the heat; strain. Whisk in some
lobster butter.