Virginia Turnip and Red Onion Soufflé

Introduced to America in the seventeenth century by French and English settlers, white turnips were almost immediately cultivated in Virginia (by colonists and Indians alike) and eventually became a favorite vegetable throughout the South. While today turnips are still primarily boiled and mashed with butter, sliced and fried, or incorporated in various casseroles, they can also serve as a foundation for much more sophisticated dishes, such as this beguiling soufflé, which a friend’s sister