The meatballs are then placed back in the skillet I used to cook the onions, drizzled with a little balsamic vinegar, and then baked for a 35 minutes. (fedandfit.com)
At the end of the cooking process you might want to add a little balsamic vinegar or wine to help deglaze the pan and bring some additional flavor to the onions. (simplyrecipes.com)
A little balsamic vinegar is added to liven things up, then more fresh pesto is drizzled on top. (foodtasia.com)