In a frying pan, heat 2 Tbsp olive oil over medium heat and sauté the
onion, garlic and celery with thyme until the onion is soft. Stir this
mixture into the soup base. Simmer the soup until the root vegetables are
tender. Add cubes of fish, return to a simmer and cook 5 more minutes
until fish is flaky and cooked through. (Substitute corn for a vegan chowder.) Just before serving, add the
chopped parsley and a few generous grindings of pepper. Taste for salt
and add more if needed.