2 medium onions, finely chopped
3 medium shallots, finely chopped
3 tablespoons unsalted butter
1 tablespoon vegetable oil
1 tablespoon all-purpose flower
2 cups white wine
1/2 cup cider vinegar
2 tablespoons tomato paste
2 tablespoons Dijon Mustard
Salt and freshly ground white pepper
2 tablespoons finely chopped fresh parsley, for serving
- In a 2 quart saucepan, sauté the onions and shallots in the hot butter and oil over medium heat for 3 minutes until translucent.
- Sprinkly the flour over the onion mixture and cook, stirring frequently, until well combined.
- Stir in the wine, vinegar, tomato paste and mustard. Reduce the heat and simmer, uncovered, for 30 minutes, until reduced by one fourth.
- Season with salt and pepper to taste.
- Keep warn until ready to serve. Before serving, stir in the parsley.