1. To make a shellfish butter, divide the butter and crustacean shells into 4 equal parts. Process one part of each (butter and shells) in a blender or food processor until the shells are finely crushed and the butter is incorporated. Repeat with the remaining 3 batches.

2. Heat the olive oil in a large stockpot over medium heat.

3. Add the shellfish butter and sauté for 4 minutes, until the mixture appears dry.

4. Add the onion, carrot, celery, leek, garlic, tomatoes, peppercorns, and fresh herbs. Simmer until the liquid is absorbed.

5. Add the white wine and simmer until the liquid is absorbed.

6. Add the brandy and simmer until the liquid is absorbed.

7. Add the water, bring to a boil, reduce heat, partially cover, and simmer for 1 hour.

8. Strain the stock through a fine sieve, pressing the shells and vegetables with the back of a spoon to extract all the juice.

9. Chill.

10. Remove the butter layer from the surface and reserve for another use, such as using in place of butter or oil in sautéing.