1. In a large, heavy-bottom pan, warm 2 Tbsp. oil over medium heat. Cook onion, stirring frequently, until very soft and translucent, 10 to 12 minutes.
2. Stir in peppers, garlic and bay leaf. Cover and cook, stirring occasionally, until vegetables are very soft, about 20 minutes. Add water a tablespoon at a time if mixture seems dry or begins to stick to pan.
3. Remove from heat and season with salt, pepper and lemon juice. Discard bay leaf. Transfer to a serving bowl, drizzle with remaining oil and sprinkle with parsley. Serve alongside grilled fish or chicken, spread on top of a pizza or bruschetta or use to fill an omelet.