To prepare salad, place first 3 ingredients on a large baking sheet coated with cooking spray. Lightly coat onion mixture with cooking spray; broil 8 minutes or until onion and bell peppers begin to blacken, stirring once. Place onion mixture in a bowl; cool. Add tomato and cilantro to onion mixture.
To prepare the dressing, remove 1 chile from can, and chop to measure 1 1/2 teaspoons. Reserve the remaining chiles and sauce for another use. Combine the chile, vinegar, oil, and salt, and stir with a whisk. Drizzle over onion mixture; toss gently to coat.