You can use any type of mustard for this dressing,
regular, horseradish, Dijon or stone ground.
White or cider vinegar is fine, too. I use onion
flakes that I grind in a mortar and pestle. This
is a variation of a recipe I found some time ago.

low sodium salad dressing makes about 2 cups
1/2 cup mustard 2 Tbsp maple syrup
1/4 cup red wine vinegar 1 Tbsp lemon juice
1 cup olive oil 1 tsp garlic powder
1 Tbsp onion powder fresh ground pepper
Mix all the ingredients in a blender until smooth. Serve over your favorite greens.