So I made the Acorn Squash with the Browned Butter Orange Vinaigrette (link below) as a side this evening. It came out wonderfully, but something strange happened to the vinaigrette. I prepared the reduction ahead of time, and just after removing the squash from the oven, whisked in the cold butter and parsley. It came together nicely, and I turned my attention to removing the squash from the baking pan. Around 60 seconds later, when I returned to the vinaigrette, it seemed that the butter has completely separated out. I tried further whisking to reintegrate the components, and it formed something the consistency of an aioli. It still tasted wonderful, so the dish worked out, but I'm not quite sure what happened or why. Any thoughts?