Clean celery, cut and sprinkle with juice of one lemon. Peel onion and garlic, dice finely.
Sauté onion and garlic in fat, briefly add celery, douse with clear soup and simmer on low heat for about 20 minutes.
Blanch tomatoes hot, skin, remove seeds and cut into small cubes. Cut chives into small rolls.
Finely blend soup with whipped cream, season with salt, pepper and tarragon. Fold in chives. Serve in soup plates with tomato pieces and croutons.
Tip: As an alternative to fresh chives, you can also use the freeze-dried.