Mix the cleaned and cut vegetables and garlic together and place into a shallow baking dish, 13" x 9" x 2". Sprinkle parsley over the top and grind black pepper over all. At this point you can refrigerate the casserole until ready to bake it.
Preheat the oven to 350°F.
Pour bouillon into a small saucepan, then add oil, salt, tarragon, and bay leaf. Heat to boiling and correct seasoning if necessary. Pour over vegetables. Sprinkle the fresh thyme over the vegetables.
Cover the baking dish with aluminum foil or parchment paper and bake at for 1 to 1 1/2 hours or until the vegetables are just tender and are still colorful. Carefully stir the vegetables occasionally while cooking, but, to preserve their color, don't lift the cover off for long.
Leave the cover off for the last few minutes of cooking time if you want the juices to cook into the vegetables more.