If using fresh chestnuts, score them with a sharp paring knife and place in a pot with enough water to cover by 2 in/5 cm. Bring to a boil over high heat, reduce the heat, and simmer until the chestnuts are soft, about 35 to 40 minutes. Drain the chestnuts and peel. If using sous vide chestnuts, put the bag in boiling water and cook according to the package directions.

Put the leek cylinders in a bowl of cold water and swish around with your fingers, changing the water several times if necessary to rid the leeks of dirt and sand. Rinse thoroughly and set aside. Cut the celery into 1-in/2.5-cm pieces. If using Chinese celery, finely chop.

In a large, wide pot or deep frying pan, heat half the olive oil over medium heat. Add the leeks, celery, and carrot. Cook, covered, stirring occasionally, until the leeks begin to brown very lightly, about 12 to 15 minutes.

Sprinkle the leeks with flour and stir for a minute or so, and pour in the wine. When the wine steams up, add enough water to come about half way up the vegetables. Add the chestnuts, vinegar, and salt and pepper to taste. Cover and simmer until the sauce is thick and the leeks tender, about 20 to 25 minutes. About 5 minutes before the leeks are done, stir in the olives. Adjust the seasoning and remove from the heat. Discard the carrot halves. Pour in the remaining olive oil and stir.