- In a bowl, combine all the ingredients. Set aside.
- In a non-stick skillet, brown the onion slices in the oil for about 2 minutes per side. Season with salt and pepper. Add the vinaigrette and remove from the heat. Refrigerate for about 30 minutes or until lukewarm.
- Drain the onions, keeping the dressing aside. Split the onion slices into rings.
- In a bowl, toss the lettuce with the vinaigrette. Adjust the seasoning.
- Divide the lettuce among four plates. Top with the onion rings and cheese slices. Serve with the toasted baguette slices.