Combine garlic, butter, and oil in a microwave-safe dish or in a small saucepan. Heat garlic and butter and oil in the microwave for 1 minute or in a small pot over moderate-low heat for 3 minutes.

Toast split bread under the broiler. Remove bread when it is toasted golden brown in colour. Brush bread liberally with garlic oil. Sprinkle with cheese, if using, and parsley. If you added cheese, return to broiler and brown 30 seconds. Cut into chunks and serve.