I was really disappointed in this dip. All I could taste was the raw balsamic vinegar. I added everything I could think of - more salt and paprika, black pepper, chipotle powder, salsa, lime juice - and it only barely improved. Now I have a giant bowl of it to take to a dinner party tonight, and I'm embarrassed to serve it. Hopefully warming it up and adding cheese will help. The only thing I can think of to do differently is to cook the balsamic with the onions.
It takes a bit longer then 10 minutes to carmelize the onions. So good!!!! I like it on my toast in the morning.