Caramelized Onions

These are so good on french dip, burgers, philly cheesesteaks, polish dogs and brats.

2 tablespoons butter
2 tablespoons olive oil
5 medium onions sliced into 1/4 inch thick rounds
salt to taste
2 tablespoons sherry vinegar

Add butter and olive oil to a large skillet or sauce pan, preferably stainless steel. This technique is easier in a non-stick pan, but it will take longer to caramelize the onions. Heat oil on med-high until the butter froths a bit. Add the onions, turn heat to medium-low, add salt, and put lid on pan. Let onions sweat for 10 minutes or until translucent. Turn heat to medium and cook the onions stirring often for 15-20 more minutes or until golden brown. Deglaze with the vinegar and serve a top any type of meat or veggie sandwich.