Best Caramelized Onions - cooking recipe

Ingredients

3 lbs onions, sliced 1/8 inch thick
8 tablespoons butter
3 tablespoons red wine vinegar
salt & freshly ground black pepper

Preparation

Melt the butter in a large skillet, add the onions.
Cover and cook over low heat 30 minutes.
Remove cover, raise the heat, stirring to keep the onions from sticking.
As soon as the onions begin to brown- in about 10 minutes- lower the heat.
Cover and cook for 10 minutes.
Repeat step 2.
Repeat step 3.
Add the vinegar, salt and pepper.
Turn the heat to high and stir with a wooden spoon until the vinegar is evaporated~ about 5 minutes.
This dish can be made in advance.
To reheat: cook over low heat for 10 minutes.
Large, mild-flavored onions work best.
Caramelized onions can be frozen in an airtight container up to three months.