This is named after Andy's former barbecue team, the UFO Social Club, which took its name from Harpoon Brewery's UFO Hefeweizen brew. Andy suggests you “slather it on right before serving.”
In a large heavy-bottomed saucepan, heat the oil over medium-high heat, then saute the onion, stirring frequently until golden brown, about 10 minutes. Add the remaining ingredients and bring to a boil. Reduce heat to very low and simmer 2 hours, stirring occasionally, scraping the bottom to prevent scorching. Transfer the barbecue sauce to a food processor or blender and puree (in batches, if necessary).