The season for pea shoots (dau miu) is brief; unlike many fruits and vegetables, you can only find pea shoots in the winter. What are they? The leaves (and sometimes the tendrils) of snow pea plants. When are they in season? They usually come on the market in late October/early November but the ones at the start of the season tend to taste very 'green'. The season lasts until late January/early February but crops from the last weeks can be tough and woody. What to look for: small leaves are more tender than larger ones. They should be fresh, moist and bright. Avoid leaves with long stalks, which are tough. What else? Pea shoots are delicate - they bruise and wilt easily. Cook them the same day you buy them. How to use: pea shoots are sometimes eaten raw in salads, but they taste better cooked. The best preparation is served at Shanghainese restaurants, which smother the stir-fried dau miu with a sauce made from the rich roe and meat of hairy crabs, another winter ingredient. This is an expensive treat and not easy to make at home. A simpler preparation is to stir-fry the pea shoots with fat, preferably rendered chicken fat. Add some minced garlic and a slice of peeled ginger and cook until fragrant. Stir in a ladleful of chicken broth and a sprinkling of salt. Cover the pan with the lid and let the vegetable cook until tender then stir in a little sesame oil or additional chicken fat and serve immediately. For a fusion dish, make risotto with pea shoots and fresh fava beans, which can be purchased from shops selling Shanghainese ingredients (buy the favas removed from their thick pods and peeled of the tough skin). Blanch the favas in salted water until tender, then drain and set aside. Cook the pea shoots in butter until wilted then set aside. Heat unsalted butter in a saucepan, add diced onion and cook until tender. Add risotto rice (such as carnaroli or arborio) and stir to coat the grains with the butter. Cook over a medium heat, stirring constantly, as you add hot chicken broth (diluted, if canned) about 100ml at a time. When the rice is al dente and slightly soupy, stir in the pea shoots, the favas and freshly grated parmesan cheese. Taste for seasoning and add salt and pepper. If you can't find fava beans, use frozen petits pois that have been blanched in boiling water.