Heat oil in large heavy pot. Add onion and celery and cook until tender. Stir in carrots and potatoes and toss to coat. Stir in zucchini. Add chopped tomatoes and stock and bring to a boil. Reduce heat so that soup simmers until the potatoes and carrots are tender about 15 - 20 minutes. Stir in pasta and peas and simmer for 5 minutes. Serve hot.