Carmelized Onion Sweet Potatoes

My friend Lynn found this one many years ago.  It's the only reason sweet potatoes made it onto our Thanksgiving table, as none of us were big fans of the mashed, sweetened variety with marshmallows on top.

The original recipe is posted here:
http://www.bhg.com/recipe/vegetables/mashed-sweet-potatoes-with-caramelized-onions/


We've made a few changes, but not many.

Carmelized Onion Sweet Potatoes   

4-8 Tablespoons butter
2 pounds yellow onions, peeled, halved, and thinly sliced (7 cups)
1/2 teaspoon salt
1/2 teaspoon freshly ground black pepper
4 pounds sweet potatoe
1/2 cup milk
1/3 cup sour cream

Directions
To caramelize the onions, in a large skillet heat 2-4 Tablespoons of the butter over low heat. Add the onions and cook, stirring frequently, about 1 hour or until golden brown, very soft and sweet. Season with the 1/2 teaspoon salt and pepper. Remove from the heat; set aside (This can be done in advance)

Poke holes in the potatoes with a fork and roast them for about an hour at 400 degrees.  This can be done the day before, then peel and mash them.
(The other option is to peel and chop the potatoes into 1/2 inch cubes.  I don't know if you've ever peeled and chopped a raw sweet potato, but it's a pain!)

Add the remaining butter to the hot mashed potatoes and let melt.  If your potatoes aren't hot enough to melt the butter, just melt it over medium low heat and add it to the potatoes. Stir in the milk, sour cream, and salt and pepper to taste. Stir in caramelized onions, reserving a few onions for garnish. Cook and stir over low heat until heated through. Transfer to a serving dish. Top with reserved onions.

If you are making it advance, skip the "heat it through" step and put it in the fridge overnight.  Then, cover it and put it in the oven with everything else and heat it through.  It will probably take 30- 45 minutes at any temperature from 325-375.

Makes 8 to 10 servings.


-Jennifer