French Onion Style Sweet Potatoes

Warm, sweet and delicious. These sweet potatoes are the best version of this side dish I have ever eaten. I mean that! French Onion Style Sweet Potatoes.

French Onion Style Sweet Potatoes 

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  • 3 pound sweet potatoes, (whole and unpeeled)
  • 2 pound onions (peeled and sliced)
  • 8 tablespoon butter (divided) or more to taste
  • 1 tablespoon kosher salt
  • fresh ground pepper
  • 1 cup marsala wine (or more to taste)
  • 1 cup chicken stock
  • 1 cup grated parmesan cheese, grated (plus more as garnish)


Pre heat the oven to 400 degrees F. and put the potatoes into the oven on a foil-lined tray. They can be messy.

Roughly chop the onions. Melt the 3 tablespoons butter in a large skillet and add the onions to the pan along with 1 tbsp salt and some pepper. Cook the onions over low heat. This needs to be a long, slow process. Two pounds will take more than an hour to caramelize properly, depending on the onions. The moisture in onions can vary greatly.

Once the onions have caramelized and given up most of their liquid, they will begin to break down and get a bit pasty in texture. This is the time to add about ½ cup sweet Marsala wine to the pan. Use a wooden spoon scrape the bottom of the pan and break loose all the little bits that might be stuck down there. Keep stirring until the pan is nearly dry again and the onions are quite sticky.

Add another ½ cup of Marsala and repeat the whole process. I call this a “French onion” process and it will yield a mass (about 2 cups) of brilliantly flavorful onions.

When the potatoes are quite soft all the way through place them on a rack to cool. Put the rack over the baking dish because the potatoes tend to drip sweet, sticky, syrup that is a bear to clean off counters once it has dried.

As soon as the potatoes are almost cool enough to handle peel the skins off of them. If you do this while they are still quite hot it is an easy job.

Put the peeled potato into a mixing bowl along with 1‑cup chicken stock, 1 cup grated Parmesan cheese, remaining 5 tablespoons butter, about 3/4 of your “French Onion” onions, and some black pepper.

Mix these all together very well. You may use a wooden spoon to get a rustic texture with bits of onions mingled throughout the potatoes. Or you may use a food processor for a more whipped texture.

If you have worked quickly the potatoes should still be hot and ready to serve. But they also make ahead nicely and may be re-warmed in the oven. Either way, adjust your seasoning before serving. Use the last of the onions as garnish and some more Parmesan if you like.