Step 1

Preheat oven to 425 degrees F. Combine tomatoes, bell peppers, onion wedges, and garlic in a large bowl. Add oil, kosher salt (or sea salt), and ground pepper; toss to coat. Transfer the tomato mixture to a foil-lined shallow roasting pan.

Step 2

Roast for 35 to 40 minutes or until the vegetables are tender and slightly charred on the edges, stirring twice. Cool slightly on a wire rack.

Step 3

Transfer the tomato mixture to a food processor. Cover and pulse until the tomato mixture is chopped but still slightly chunky. Stir in balsamic vinegar and thyme. Stir in basil just before serving.