Heat oil in a saucepan over medium-high heat. Add onion; cook, without stirring, until onions darken, about 5 minutes. Pour sherry wine into the pan. Simmer to cook off alcohol, about 1 minute. Stir in tomato juice, soy sauce, pomegranate molasses, ketchup, vinegar, Worcestershire sauce, pineapple juice, espresso, and chipotle peppers; bring sauce to a boil.
Reduce heat to low until sauce is just simmering. Add brown sugar; stir well to dissolve. Simmer sauce, stirring occasionally, until flavors are combined, about 20 minutes. Strain sauce to remove onions and chipotle peppers. Refrigerate until cool.