Step 1Cut the onion, tomatoes, potatoes, eggplant and red and yellow bell peppers into 1-inch cubes. In a large skillet, cook the onion in the oil over medium-low heat until tender, about 5 to 8 minutes.
Step 2Add the tomatoes, potatoes, eggplant and peppers. Add salt and pepper to taste. Cover and cook, stirring occasionally, until all the vegetables are tender and most of the liquid is evaporated, about 40 minutes. If the mixture becomes too dry, add a couple of tablespoons of water. If there is too much liquid, uncover and cook 5 minutes more.
Step 3Serve the ciambotta warm or at room temperature plain or with basil or cheese.
Variation: Ciambotta With Eggs: When the vegetables are ready, beat 4 to 6 eggs with salt until blended. Pour the eggs over the vegetables. Do not stir. Cover the pan. Cook until the eggs are set, about 3 minutes. Serve warm or at room temperature.