Heat oven to 375°F. Spray 2-quart oval casserole or 11x7-inch (2-quart) glass baking dish with cooking spray. In 10-inch nonstick skillet, heat oil over medium-high heat. Add onion; cook about 5 minutes, stirring occasionally, until golden brown. Stir in garlic and chile; cook 1 minute, stirring constantly. Stir in tomatoes; cook until thoroughly heated. Remove from heat.