1. Heat oil in a large (4 1/2 qt) Dutch oven. Add chicken and brown about 15-20 minutes.
2. Remove chicken and add onion, garlic and celery to pan; saute on medium heat about 5 minutes.
3. Return chicken to the pan with vegetables. Add tomatoes, chicken broth, wine, salt, pepper, sage, thyme and bring to a boil; then turn down and let simmer for 45 minutes to 1 hour.
4. Add squash, bring to boil then simmer for 30 minutes or until squash is tender.
5. Debone chicken. Stir in frozen peas and reheat for a minute or two.