Long and thin and resembling the yellow-green color of a zucchini, an opo is sometimes referred to as a melon. A variety of Chinese squash, opo squash has a tender white flesh when young. Mature opo squash should have seeds removed before eating. Prepare opo squash as you would summer squash or zucchini; steam or sautee, roast, add to soups or stews, or simply eat it raw. It is available year-round, with supplies peaking during summer and fall.