Heat the oil in a large skillet over medium heat, add the garlic and onions. Saute', stirring frequently and cook for approximately 10 minutes or until tender.
Add the stock, raise the heat to high and cook for approximately 7 minutes until the liquid is reduced by 1/2. Add the mustard, honey, vinegar; salt and pepper to taste. Reduce heat to med-low and simmer for 10-15 minutes. Liquid will almost all evaporate.
Remove from heat and allow to sit for 10-15 minutes. Serve warm, but not hot.
Will keep refrigerated for 5-7 days or frozen for 3-4 months.