Chipotle-Cherry Barbecue Glaze

In a small saucepan, melt the butter. Add the onion and cook over moderate heat, stirring occasionally, until softened, 5 to 6 minutes. Add the remaining ingredients and cook over moderate heat, stirring, until bubbling, about 5 minutes longer. Transfer the mixture to a food processor and process until fairly smooth. Transfer to a bowl and let cool before using.