1. In a large, deep skillet, heat 3 tablespoons of the olive oil. Add the peppers and season with salt. Cover and cook over moderate heat, stirring occasionally, until softened, about 18 minutes. Transfer the peppers and their juices to a bowl.
2. Wipe out the skillet. Heat the remaining 2 tablespoons of olive oil in the skillet. Add the garlic and cook over moderate heat until golden, about 3 minutes. Add the capers and the reserved peppers and their juices. Cook, tossing, until the peppers are warm; season with salt. Transfer the peppers to a bowl and serve warm or at room temperature.