If you are cooking that day, Preheat oven to 400 degrees.
In a small bowl combine scallions, carrots, zucchini, tarragon, zest and olive oil.
Place each chicken breast seperately on a folded piece of parchment that is 1 foot square. Spoon on 1/4 vegetable mixture to each chicken breast and fold parchment.
Bake in the oven for 20 minutes.
Serve hot.
If you are making ahead, use foil instead of parchment. Cook 25 to 30 minutes.