Cook artichoke according to package directions; drain. Combine with salad dressing, chicken, water chestnuts, olives, and soy sauce. Cover and refrigerate at least 3 hours. Melt butter; add pecans and cook over low heat, stirring constantly until nuts begin to brown. Drain nuts and sprinkle with vegetable seasoning; cool. Drain any liquid from chicken mixture. Add celery just before serving. Serve on lettuce leaves and garnish with pecans.