This quintessential French sweet-and-sour sauce is a wonderful way to dress duck and beef, especially when the meat is seared. The ingredients are simple: sugar, vinegar, and fruit juice or purée. Here is the classic gastrique recipe, but have fun experimenting with different combinations using this basic technique.
- 1/2 cup white sugar
- 1/2 cup red wine vinegar, such as Vinagre de Touriga Nacional
- Juice of one orange
In a sauté pan over medium heat and without stirring, slowly heat the sugar until it caramelizes. Lower the heat and carefully whisk in the vinegar.
Next, add the juice, whisking continuously (if the mixture hardens, the heat will melt it again). Continue cooking until the liquid reaches a syrupy consistency, but don’t let it get too thick or it will solidify—take it off the heat just before you think it’s done.
Yields about a 1/4 cup, enough to sauce two portions of your chosen protein