- 2 tablespoons extra-virgin olive oil
- 2 lbs. langoustine shells, rinsed but left whole (or substitute shrimp or lobster shells)
- 2 oranges, preferably organic, rinsed and quartered
- 1 tablespoon fennel seeds
- 2 whole pieces star anise
- One 28-ounce can Italian plum tomatoes in their juice (do not drain)
- Several fresh or dried bay leaves
- 1 plump, moist head garlic, halved crosswise but not peeled
- 1/4 teaspoon ground chile pepper, or piment d'Espelette
- 1 teaspoon fine sea salt
- 1 tablespoon tomato paste
In a heavy-duty roasting pan or in a large, deep skillet, heat the oil over moderate heat until hot but not smoking. Add the shells and sear until they turn bright pink, 2 to 3 minutes. Add the orange quarters, fennel seeds, star anise, 4 quarts cold water, the tomatoes, bay leaves, garlic, chile peppers, sea salt, and tomato paste. Bring to a boil, uncovered, and boil vigorously for 30 minutes. To extract the maximum flavor from the shells, use a wooden mallet to crush and break them up while the soup is cooking.
Line a large colander with a double layer of dampened cheesecloth, and place the colander over a large bowl. Ladle the broth into the colander, discarding the solids.
Taste for seasoning. Serve warm in small cups as an appetizer, or in warmed shallow soup bowls as a first course.