• 4 tablespoons extra-virgin olive oil
• 1¼ pounds eggplant, diced into ½-inch cubes
• Salt
• 1¼ pounds red and yellow bell peppers, cut into ½-inch pieces
• 2 garlic cloves, thinly sliced
• ½ cup tomato puree
• 3 tablespoons salt-packed capers, rinsed, soaked in cold water for 10 minutes, then rinsed again
• 1 teaspoon whole green peppercorns, optional
• ¼ cup red wine vinegar
• 1 tablespoon sugar
• Freshly ground black pepper
• Flat-leaf parsley sprigs for garnish

In a large heavy nonstick skillet, heat 2 tablespoons oil over medium-high heat until hot but not smoking. Add eggplant, in batches if necessary, and pinch salt; cook, stirring occasionally, until tender, 5 to 7 minutes. Transfer to a large bowl.

Add remaining 2 tablespoons oil and peppers to skillet. Cook, stirring occasionally, until peppers soften, about 10 minutes; add garlic and cook, stirring, 1 minute more. Stir in tomato puree, capers and peppercorns, if using. Reduce heat to medium, cover and cook, stirring occasionally, until peppers are tender and flavors have blended, about 10 minutes.

Meanwhile, in a small saucepan, bring vinegar and sugar to a boil; cook until reduced by half, about 5 minutes. Remove from heat.

Transfer pepper mixture to bowl with eggplant, stir in reduced vinegar, and season to taste with salt and pepper. Serve warm or at room temperature, garnished with parsley.