4, 1 ½-pound lobsters
1 stick butter
1 medium onion, cut into quarters
2 large carrots, chopped into large pieces
2 large celery stocks, chopped into large pieces
4 garlic cloves, smashed
1 large tomato, cut into quarters
3 sprigs fresh tarragon
1 teaspoon peppercorns
1 cup white wine
½ cup dry sherry
3 tablespoons tomato paste
3 tablespoons corn starch
½ cup milk
1 cup heavy cream
Place the lobsters in a large pot of boiling water for about 10-12 minutes. Let cool and then shuck the lobsters, removing all of the meat from the tail and claws. Chop meat into bite-size pieces and set aside. Reserve the bodies and shells.
Place the butter into a large Dutch oven (6-8 quarts) or soup pot along with onion, carrots, celery, and garlic. Cook over medium high heat, stirring frequently, until vegetables begin to soften and are fragrant, about 10 minutes. Add the shells back into the pot along with the tomato, tarragon, and peppercorns and continue to cook for another 10 minutes, stirring frequently.
Add the white wine to the pot and enough water to barely cover the shells, about 4 cups. Bring to a boil, pushing the shells into the liquid. Cover and reduce heat to low and let simmer for one hour.
Strain the stock into another pot through a fine sieve. Add the sherry and tomato paste to the strained broth and bring back to a boil. Let boil for 20 minutes until liquid is roughly reduced by half, leaving about 4 cups. Mix cornstarch and milk in a small bowl until cornstarch is dissolved. Add to the boiling liquid and let it thicken. Turn off the heat and let the broth cool to ‘warm’.
Add the heavy cream to the pot and slowly bring up to a simmer, careful not to curdle the cream by boiling. Let simmer for 20 more minutes. Add the reserved lobster meat to the pot and simmer 5 more minutes.
Garnish with chopped tarragon or chives.