- 2 lbs yellow onions
- 2 tsp kosher salt
- 3 tbs sugar
- 4 tbs unsalted butter
- 1 tbs balsamic vinegar
- Halve the onions and remove the tough outer layers, then cut the onion halves into thin slices.
- Place the onion slices in a plastic bowl, sprinkle with salt, sugar and balsamic vinegar and toss.
- Set aside for 15 minutes.
- Melt the butter over medium heat in a large cast iron skillet or saute pan.
- Add the onion. Reserve any liquid left in the bowl.
- Cook over medium heat watching closely, stirring and tossing often with a spatula until the first browning is visible.
- Reduce the heat and add the liquid from the bowl.
- For the best result, reduce the heat to the lowest possible setting, cover the pot and cook for 1 hour or more, stirring every 10 minutes or so.