These are marvelous to take along on a picnic. For extra glamour, package them in tiny bundles “tied” with pimiento strips.
In a wide saucepan, combine wine, oil, and 3 cups of water. Stir in thyme, salt, fennel seeds, peppercorns, and bay leaf. Add scallions, parsley, lemon zest, and celery leaves and bring to a boil.
Drop beans into the boiling liquid and cook, uncovered, for 6 to 8 minutes or until crisp-tender. Lift beans out with a slotted spoon and place in a deep rectangular dish. Continue to boil liquid until it is reduced by half. Stir in lemon juice and tarragon, and pour over beans. Cover dish with wax paper, then with aluminum foil. Refrigerate for 24 hours.
Remove beans from the liquid and divide into 8 small portions, lining them up like bundles of sticks. Wind a narrow strip of pimiento around each bundle and overlap the ends. Serve immediately, or if packing for a picnic, enclose each bundle in a piece of plastic wrap.