Herb Crème Fraiche Mashed Potatoes with Caramelized Onions
Author note: It is important to use Yukon Gold potatoes for this recipe. Out of all the potato varieties, the Yukon Gold is one of the best to boil and mash. Also, when mashing the potatoes, use a hand held masher. If there is not a hand held masher, an electric mixer with a whipping attachment will also work. Finally, these mashed potatoes are delicious and make great leftovers. They can be easily reheated in the oven up to two days after making them.* This recipe can be doubled to serve a large crowd.
For the mashed potatoes:
1 cup crème fraiche, at room temperature
1 tablespoon fresh thyme, chopped (dried thyme is also acceptable, use 1-2 teaspoons)
zest of two lemons
5 large Yukon Gold potatoes, peeled and cut or sliced into large pieces (about 8 to 9 cups)
1 stick unsalted butter, at room temperature
¾ teaspoon kosher salt
For the caramelized onions:
2 onions, halved and sliced thin (about five cups)
2 tablespoons unsalted butter
1 ½ teaspoon kosher salt
For the Mashed Potatoes:
- About five hours before preparing this dish, set out the crème fraiche and butter.
- Next, heat a large pan of water and bring to a boil. Add the potatoes and cook until easily pierced with a fork.
- While the potatoes boil, combine the crème fraiche, thyme and lemon zest in a medium sized bowl. Stir to combine and set aside.
- Once the potatoes are cooked, drain the water and return to the pan. Place the pan away from heat and add the crème fraiche mixture, one stick of butter and ¾ tsp of kosher salt to the potatoes. Mash until the potatoes are smooth and creamy.
- Finally, add the caramelized onions to the mashed potatoes and stir to combine. Serve warm.
- To store, place the potatoes in an oven safe container and cover with plastic wrap. Place in the fridge up to 2 days before and reheat per the instructions below.*
For the caramelized onions
- Place two tablespoons of unsalted butter in a large skillet and heat to medium-low.
- Once the butter is melted, add one layer of onions and then top with ½ tsp of kosher salt. Repeat this process two more times for a total of three onion and salt layers (watch this video for a visual guide to caramelizing onions).
- Over medium-low heat, cook the onions for 20 minutes. Do not stir the onions. After 20 minutes, stir the onions well.
- Continue to cook the onions for an additional 15 minutes. Again, do not stir or touch the onions. Stir the onions after these 15 minutes. If the onions appear to be burning, lower the heat. If the onions have a nice brown color and flavor keep them at the medium-low temperature.
- Continue to let the onions caramelize for another 10 to 20 minutes. Once fully caramelized remove from the heat.
*Instructions to reheat the mashed potatoes:
- One hour before reheating, remove the potatoes from the fridge.
- Set the oven to 350 degrees and press 2 to 3 tablespoons of diced unsalted butter into the potatoes.
- Place in the oven, uncovered and reheat for 20 minutes.
- After 20 minutes, stir the potatoes and let cook for an additional 10 minutes or until warmed thru completely. Serve warm.