Turnips are mostly grown in early summer and autumn. Summer turnips are tender and peppery sweet, a bit like radish. In winter they become more heavy and dense. You can use the leaves in stir-fries.
Store
Take off the leaves and store separately. Store the leaves in a wet paper towel, they hold for about 3 days. Store the root in the fridge for a week or even two.
Recipes
Turnips are versatile, you can eat them raw, pickled, roasted or braised. You probably want to peel them, the skin can be a bit tough.
Summer turnip and leek gratin
Roasted with balsamic vinegar
Turnip and potato soup
Azian turnip salad (raw)