Peel and clean carrots and turnips, trim green beans and peel tomatoes. Place prepared vegetables in water to cover with few dashes of vinegar. Cut carrots, turnips, celery and tomatoes in julienne strips, about 5 cm in length. Heat chicken broth along with 1 tablespoon butter. Cook cut vegetables separately in broth, simmering 1 to 4 minutes until they are tender but firm, depending on their type and size. Cook green beans and peas in boiling salted water until tender but crisp. Plunge in ice water to prevent cooking further, then drain. Decorate large platter with mache and radicchio. Make arrangement of vegetables on lettuces. Combine shallots, parsley, 6 tablespoons vinegar and oil in bowl. Season to taste with salt and pepper. Sprinkle vinaigrette over vegetables and garnish with truffles.