A unique twist on a summertime favorite, this sweet and tangy barbecue sauce will be great on chicken, steak or slathered on a hamburger.
Heat olive oil in a 4-qt. saucepan over medium-high heat.
Add onions and cook until soft, about 5 minutes. Stir in the garlic and cook until fragrant, about 1 minute.
Stir in the remaining ingredients and continue to stir until the chocolate has melted and the sugar has dissolved.
Continue cooking at a low simmer, stirring frequently, until the sauce has thickened, about 10 minutes.
Taste and adjust salt if needed.
Serve right away and save the remaining sauce refrigerated in an airtight container for up to 2 weeks.