1 large onion, 2–3 carrots, and 2–3 stalks of celery, all diced.
1 meaty ham bone (or ham hocks) is preferred for depth of flavor, but 2 cups of diced ham can be used as a substitute. ham and pea soup recipe
1 lb (approx. 2 ¼ cups) dried green split peas, rinsed. 1 large onion, 2–3 carrots, and 2–3 stalks