The delicately flavored fruit chayote is ubiquitous in the central highlands of Mexico. It varies greatly in size, ranges in color from white to dark green, and can have prickly or smooth skin. The variety most commonly available in the United States (also known as a vegetable pear or mirliton) has smooth, pale green skin that can be eaten but is sometimes removed.
Cooks' note:
• Soup can be made 1 day ahead and cooled, uncovered, then chilled, covered. Reheat before serving. *Available at Latin markets and some supermarkets.