1. Sweat the vegetables and herbs in olive oil.
2. Deglaze with white wine. Reduce by half.
3. Add the stock; bring to a boil and cook for 30 minutes.
4. Let rest for 10 minutes and strain.

Barigoule Vegetables

1. Cook the vegetables (except the truffle) in a covered pot with the barigoule stock - they should remain just slightly crisp.
2. Remove the vegetables from the stock and let cool.
3. Reduce the liquid to the consistency of a sauce.
4. Whisk in some olive oil to create a foamy sauce; season with salt and pepper.
5. Add the chopped truffle.

Roast Langoustines
Sauté the langoustines in olive oil, seasoning them on the underside.

Presentation

1. Place the cold vegetables in a deep plate.
2. Arrange the langoustines attractively on top.
3. Spoon on some of the foamy sauce.
4. Garnish with truffle slices and sprigs of chervil.