This buttery-sweet topping is wonderful served in sandwiches or atop bratwurst!
2 yellow onions
2 tablespoons vegetable oil
1 tablespoon balsamic or sherry vinegar (optional)
1. Peel and slice the sweet onions. Heat a bit of vegetable oil in a large frying pan over medium heat.
2. Add sweet onions, sprinkle with salt, reduce heat to medium low or low and cook, stirring frequently, until onions are extremely tender and caramelized, about 30 minutes. Keep heat low enough so onions are cooking but not browning; caramelizing will brown them inside-out rather than bits of browning on the outside first. Finish with a splash of balsamic or sherry vinegar, if you like.