2 tsp Kosher salt
2 live lobsters, weighing around 3 pounds total
1# Alaska Spot Prawns or Shrimp 21/25 w/ shells
2 tablespoons olive oil
1 carrot, chopped
2 ribs celery, chopped
1 medium onion, chopped
2 cloves garlic, crushed
2 sprigs fresh thyme
2 sprigs fresh tarragon
2 tablespoons tomato paste
1 cup medium sherry
2 cups clam broth
1 cup heavy cream
Cayenne pepper, to taste
Fill a large pot with 1/2 inch of water. Stir in 2 teaspoons kosher salt and bring the water to a boil. Add the lobsters, cover with a tight-fitting lid and return the water to a boil. Once boiling, lower the heat to a gentle boil and cook the lobsters until they are bright red, about 12 minutes. Remove the lobsters, reserving the liquid. When the lobsters have cooled slightly, place them in a bowl and remove the meat from the claws and tail, again reserving any liquid that comes out of the shells. Chop the meat and refrigerate. Roughly chop the shells into small pieces and reserve, along with all the lobster remains. Clean the shrimp, saving the shells.
Swirl the olive oil in a large pot over medium heat, then add the vegetables and herbs. Sweat until the onions are translucent, about 5 minutes, then increase the heat to medium-high and add the lobster and shrimp shells. Sauté for 5 to 6 minutes, then add the tomato paste and cook for an additional 3 to 4 minutes.
Add the sherry, then ignite or cook until the alcohol has evaporated. Add the clam broth and 1 cup of the lobster-cooking liquid. Bring to a simmer and cook, covered, for 1 hour.
Strain the broth through a colander, then pass through a fine sieve. Add the cream and bring to a low simmer. Add the chopped lobster meat and shrimp let it heat through until the shrimp are just cooked through, then season to taste with salt and cayenne.