Best Caramelized Onions

Directions

1. 1
   Melt the butter in a large skillet, add the onions.
2. 2
   Cover and cook over low heat 30 minutes.
3. 3
   Remove cover, raise the heat, stirring to keep the onions from sticking.
4. 4
   As soon as the onions begin to brown- in about 10 minutes- lower the heat.
5. 5
   Cover and cook for 10 minutes.
6. 6
   Repeat step 2.
7. 7
   Repeat step 3.
8. 8
   Add the vinegar, salt and pepper.
9. 9
   Turn the heat to high and stir with a wooden spoon until the vinegar is evaporated~ about 5 minutes.
10. 10
    This dish can be made in advance.
11. 11
    To reheat: cook over low heat for 10 minutes.
12. 12
    Large, mild-flavored onions work best.
13. 13
    Caramelized onions can be frozen in an airtight container up to three months.