Robert Sauce - T. H. E. Pork Sauce - cooking recipe

Ingredients

1 tablespoon unsalted butter
1 medium onion, peeled and finely chopped
2/3 cup dry white wine
1 cup demi-glace (More Than Gourmet) or 1 cup thickened veal stock (jus de veau lie)
1/4 teaspoon sugar
1 1/2 teaspoons Dijon mustard

Preparation

Heat butter in a skillet until foam subsides. Add onion; saute until softened but not browned.
Add the white wine and reduce by two-thirds.
Add the demi-glace or jus de veau. Bring to a boil, then reduce heat and simmer for 10 minutes.
If you want bragging rights, strain the sauce through a chinois to produce a very smooth sauce. Otherwise, transfer directly to a bain-marie to hold warm until ready to use.
Just before serving, stir in the sugar and mustard.