In a large bowl, combine the watercress, lettuce, mushrooms, and onions. To make the dressing, in a small bowl whisk together the mustard, red wine vinegar, red wine, garlic, and chives.
Gradually whisk in all the oil, and continue mixing until an emulsion forms. Add the salt and pepper and mix well. Toss the dressing as desired on the salad. Crumble the cheese on top and serve.
Pair with the same Merlot as in the dressing.
Yield: 6 servings