Prepare the vinaigrette: Place chicken stock in a saucepan and reduce liquid to 1/2 cup. Pour hot chicken stock over the shallots in a blender and let sit for 3 minutes. Add the vinegar and season to taste. While the stock is still hot, slowly add the oil with the blender on medium speed to emulsify. Add truffle peelings and blend briefly. Keep warm until ready to serve.