Direction

1. Fill a large bowl with ice water. Bring 6 cups water, tarragon, thyme, bay leaf, and salt to a boil in a 6- to 8-quart pot over medium-high heat. Add lobster tails. Return to a boil; reduce heat to medium. Simmer until shells turn bright red and meat is tender, 6 to 10 minutes. Remove tails and immediately plunge into the ice water.
2. When cool enough to handle, remove meat from shells (see “Lobster Prep,” below). Return shells to pot. Simmer, covered, over medium heat to develop flavor, about 30 minutes. Stock may turn a green color from the herbs.
3. Meanwhile, coarsely chop lobster meat. Chill, covered, until ready to use (up to 3 days).
4. Strain 4 cups of the stock through a fine-mesh sieve into a large glass measuring cup; discard solids.
5. Melt butter in the same pot over medium heat. Cook onion, carrots, and celery, stirring frequently, until tender, about 10 minutes. Stir in garlic; cook until fragrant, about 1 minute.
6. Stir in flour to coat vegetables. Add wine and tomato paste. Cook, stirring frequently, until mixture is combined. Stir in stock; cook over medium-high heat until mixture is bubbly. Cook mixture, stirring frequently, 2 minutes more.
7. Stir in lobster meat, half-and-half, vanilla bean paste, and cayenne. Cook until heated through, about 2 minutes. Garnish servings with fresh tarragon and thyme.