The southern Italian vegetable stew known as ciambotta or cianfotta often is likened to Provençal ratatouille, but it sometimes contains potatoes, which give the dish a little more heft. We use a 12-inch skillet to make the stew; its wide surface area means that cooking happens more quickly than if the vegetables were piled on top of each other in a pot, resulting in fresher, brighter flavors, textures and colors. Serve warm or at room temperature as a side to grilled or roasted chicken, lamb, beef or fish. Or offer it finished with pecorino or Parmesan as a light vegetarian main with crusty bread alongside.