Ingredients
2 cups beef broth (if you’re using low-sodium, add 1 tsp kosher salt)
2 tsp rice wine vinegar
1 tsp brown sugar
1/8 tsp ground ginger
dash of onion powder

Method
Combine all ingredients in a small sauce pan. Simmer over low heat until reduced to 1/2 cup of liquid. Store refrigerated in an air-tight container and use within 2 weeks.

Variation
Convert this into teriyaki sauce by combining the finished product with 1 tbsp brown sugar, 2 tbsp pineapple juice, and a 1″ slice of fresh ginger. Simmer over medium heat for about 10 minutes, and then remove ginger.