2. Strain shrimp stock into a bowl, pressing on the shells before discarding them.
3. In the same pot, melt another 2 tablespoons butter with 1/4 teaspoon salt. Add the shrimp and sauté until they are pink, 2 to 4 minutes depending on size. Using a slotted spoon, transfer the shrimp to a bowl.
4. Add remaining 3 tablespoons of the butter to the pot with the celery, leeks, garlic, and fennel and sauté until softened, about 5 minutes. Stir in the rice, tomato paste, cayenne, and remaining salt and sauté for 2 minutes. Add shrimp stock and simmer, covered, until rice is tender, about 20 minutes.
5. Set aside 4 to 6 nice shrimp and stir the remainder into bisque; let cook for 2 minutes. Working in batches, pour the bisque into a blender (use caution when blending hot liquids or add a couple of ice cubes to the blender while blending), then return to the pot. Or, you can use an immersion blender to puree the soup. You can puree the soup to be as smooth or chunky as you like. Stir in the lemon juice and additional salt to taste. Reheat if necessary before serving. Garnish each bowl with a shrimp, a drizzle of Pernod if desired, and a piece of fennel frond.
Sandor Katz lives to ferment; it’s his life’s work. The author of The Art of Fermentation shares how to make kombucha at home.