Heat the oil in a nonreactive saucepan and add the carrot, celery, onion, green beans, turnips, and some salt. Cook over low heat about 5 minutes, stirring often, until the vegetables begin to soften. Add the garlic and stir a few seconds more.
Add the stock, thyme, and rosemary. Bring to the boil and cook at a brisk simmer until the vegetab