Slow-cooked peppers, tomatoes, and onions create a sweet, silky vegetarian side dish. This mediterranean classic is fresh, healthy, and a versatile family accompaniment to any Italian meal.
Cut the red and yellow bell peppers into 1/2-inch strips for even cooking and set aside.
Slice the large onion thinly and finely mince the garlic cloves to ensure even distribution of flavor.
Heat the olive oil over medium-low heat in a wide, heavy saucepan. Add the onion and cook gently for 5 minutes, stirring often, until softened but not browned.
Add garlic and bell peppers, sprinkle with salt and black pepper, and cook on medium heat, stirring occasionally, for 8–10 minutes until the peppers start to soften.
Chop the tomatoes and add them to the pan. Lower the heat to low, cover with a lid, and cook gently for 25–30 minutes, stirring every 5–10 minutes, until the peppers and onions are silky and the mixture is slightly reduced.
Remove the lid in the last 5 minutes if a thicker consistency is desired. Stir in torn fresh basil at the end, adjust seasoning, and serve warm or at room temperature.