Onion Sauce

Ingredients

• 56 g (~½ stick) unsalted butter
• 2 large yellow onions, peeled, cut in half and thinly sliced
• 2 tsp sugar
• ½ C red wine
• 2 sprigs fresh thyme
• 1 large sprig fresh sage
• 2 C strong beef broth
• 1 tsp Worcestershire sauce
• 1 tsp salt
• ½ tsp prepared yellow mustard
• ¼ tsp freshly ground black pepper
• 1 tbs dark balsamic vinegar
• 1 tbs cornstarch dissolved in 1 tablespoon water
• 2 tbs cold unsalted butter

Directions

1. Melt the butter in a saucepan over medium high heat. Add the sliced onions and sugar and cook for about 30 minutes until caramelized (deep golden).
2. Add the red wine and herbs, bring to a rapid boil for 2 minutes, reduce the heat and simmer for 10 minutes.
3. Add the stock, mustard, salt, pepper and Worcestershire sauce, bring to a boil, reduce the heat to a low simmer and simmer, covered, for 20 minutes.
4. Remove sprigs of herbs. Add the vinegar, whisk in the cornstarch and simmer another minute or two until thickened, whisking continuously.
5. Add the cold butter and whisk until dissolved. Add salt and pepper to taste and more mustard if desired.

Sauce Timeline

Step	Direction	Time (min)	Notes
1	Onions, butter, and sugar	30	Carmelize the onions
2	Wine and herbs	10	Deglaze and reduce wine
3	Stock and seasonings	20	Extend with stock
4	Vinegar, slurry, and butter	2	Finish