Using the insides of the red onion, finely diced, 1/4 pound., Place the bacon grease in a saucepan over medium-high heat. Add the onions and saute until the onions start to blacken. While the onions are caramelizing, in a mixing bowl place the water, honey, and red wine vinegar. Using a wire whisk, mix the ingredients well. Add the cornstarch and whisk well. After the onions have caramelized, add the
Dijon mustard to the onions and stir together with a rubber spatula. Add the water, vinegar, pepper, honey, and cornstarch to the mustard and onions and mix. Continue stirring until mixture thickens and comes to a boil. Remove from heat and store in the refrigerator until needed. Makes 1 quart. Note: To reheat use a double boiler. I put Tabasco on the ingredient list if you like it. In different parts of the country, Bennigan's omits this ingredient.