Italian Chicken Soup

4 chicken breasts or 4 chicken thighs 4 stalks celery 4 carrots , sliced 1 (16 ounce) box frozen spinach 2 onions , diced 2 (14 1/2 ounce) cans diced tomatoes[...]

2 tablespoons olive oil 4 boneless skinless chicken breasts , cut into bite size pieces 1 small onion , chopped 1 cup sliced carrot 2 1/2 cups sliced zucchini[...]