Once the lobster has defrosted, de-shell as per pack instructions.

Using a rolling pin or similar, bash the lobster shell into pieces about 1 square inch. Be careful, this can get messy!

Heat 25g of butter in a heavy based pan pot. Add the lobster shells and stir often. Fry the shells over a medium-high heat for 5 minutes until they turn golden and aromatic.

Deglaze the pot with white wine, leaving the lobster shells in the pot. Add fresh parsley, the fish stock and chicken stock. Bring the mixture to a gentle boil and allow it to simmer uncovered for 25 minutes, then put the lid on and allow it to simmer for another 20 minutes to retain some liquid.

While the stock simmers, sauté the carrots, celery, onions and garlic in the remaining butter until soft and fragrant. Set aside.

Once the stock has simmered for 45 minutes, strain it carefully, discarding the shells and parsley. Add the strained stock to the sautéed vegetables. Stir in bay leaves, tomato puree, and if using, the brand and sherry. Simmer the mixture gently with the lid on for an additional 45 minutes.

After the second simmering period, blend the mixture until smooth. Stir in the heavy cream and reheat gently over low heat.

In a separate pan heat a small knob of butter with half of the lemon juice. Add the reserved lobster meat and heat over a moderate heat for 1 minute, just to warm through.

Add the remaining lemon juice to the bisque and stir. To serve, place the warmed lobster meat in individual soup bowls and pour the bisque over the top. Top with more cream, fresh parsley and crusty bread.