This is a quick and delicious side dish for any season, since chicory is available year-round. Radicchio, a red-leaf chicory, adds a contrasting bitter note as well as a splash of color.
Heat olive oil in a large skillet over medium-high heat. Add anchovies, and cook 1 minute. Add radicchio and chicory; saute until slightly wilted, 1 to 2 minutes. Season with salt and pepper. Transfer to serving platter, and drizzle with balsamic vinegar.