Prepare the vinaigrette dressing by adding 2-3 tablespoons of walnut oil, 1-2 tablespoons of red wine vinegar and 2-3 tablespoons of very good quality olive oil to a bowl. Season with a pinch of salt and freshly ground black pepper. Add half a teaspoon of Dijon mustard and a sprinkle of sugar to sweeten. Mix together and add more oil/vinegar/seasoning to taste.