Mix all of the ingredients in a medium saucepan and bring to a simmer over medium-high heat. Once it is simmering, reduce to low heat and continue to simmer for 15-20 minutes, stirring occasionally, until the sauce has thickened.
Remove from heat and cool to room temperature. Transfer to an air-tight container and refrigerate for up to 2 months.
For an even spicier sauce, add ½ teaspoon crushed red pepper, or ⅛ teaspoon cayenne pepper.For a sweeter sauce, increase the brown sugar to up to ½ cup.