Stir-frying happens quickly, so line up prepped ingredients to gracefully and easily glide through the cooking process. You don’t need a giant wok for all the greens, which will collapse into a creamy, earthy side dish. Use a wide pot or pan that can take big heat. This recipe is my supermarket take on stir-fried water spinach, a go-to vegetable for everyday Viet meals. Prewashed greens don’t release much liquid, which can dilute flavors and turn a stir-fry sizzle into a fizzle.