1. Heat bacon fat over medium-high heat in small saucepan.
2. Saute onions until they are well browned.
3. Add water, honey, red wine and vinegar to large mixing bowl. Whisk ingredients well.
4. Add cornstarch and whisk to blend in.
5. Add Dijon mustard to onions and stir well with wooden spoon.
6. Add honey mixture to onions. Stir constantly until mixture boils.
7. Cool slightly and serve.