Roasted Tomato-And-Pepper Salad

Ingredients

• 6 large plum tomatoes
• Vegetable cooking spray
• 1 yellow bell pepper
• 1 green bell pepper
• 1 red bell pepper
• 1 medium-size purple onion, cut into eighths
• 1 tablespoon olive oil
• 1 tablespoon balsamic vinegar
• 1 garlic clove, minced
• 1/2 teaspoon salt
• 1/2 teaspoon dried oregano
• 1/2 teaspoon freshly ground pepper
• 1/4 cup sliced fresh basil