Description

These Caramelized Onion Mashed Potatoes are unlike any other mashed potatoes you’ve ever had! They’re perfectly rich, creamy, cheesy, and the addition of the caramelized onions really takes them over the top! These potatoes are an elevated side dish perfect for holiday meals but you’ll crave them for weeknight dinners, too.

Ingredients

Units Scale

For the Onions

2 tablespoons olive oil
1 tablespoon butter
3-4 large yellow onions, sliced 1/4 inch thick
1/4 teaspoon kosher salt

For the Potatoes

3 pounds russet potatoes, peeled and diced
4 cloves garlic, peeled and smashed
2 teaspoons kosher salt (divided), plus more to taste
4 tablespoons unsalted butter, plus more for serving
3/4 cup half and half
1/4 teaspoon black pepper
4 oz gruyere cheese, grated (plus more for topping)
thinly sliced chives, for garnish
fresh thyme, for garnish

Instructions

Make the Caramelized Onions: Heat a large pan with a lid to medium-low heat. Once hot add 2 tablespoons of olive oil and 1 tablespoon of butter. Add the onions to the pan and stir and then add the salt. Cover the pan and let the onions cook for 30-40 minutes, stirring every 5 minutes or so until the onions are a deep caramelized golden brown.
Cook the Potatoes: Add the potatoes, garlic, and one teaspoon salt to a large pot and cover with cold water. Bring the potatoes and garlic to a boil and let them cook until fork tender, roughly 15-20 minutes. Once tender, remove the potatoes from the heat and then drain completely.
Transfer the fully drained potatoes and garlic back to the warm pot and use a potato masher or hand mixer to mash the potatoes.
Add the remaining salt, butter, half and half, and black pepper and continue to mash until the potatoes are fully mashed and creamy.
Next, add half the caramelized onions and all of the grated gruyere to the mashed potatoes and fold into the potatoes until well combined. You can add a bit more half and half if you prefer for any even creamier consistency. Give the potatoes a taste and adjust the amount of salt and pepper to your taste.
Transfer the mashed potatoes to a serving dish. Top with the remaining caramelized onions, chives, thyme, and a bit more butter and grated gruyere before serving.

Notes

Store: Transfer the cooled potatoes to an airtight storage container, and store them in the fridge for 3-4 days. I do not recommend freezing this recipe!

Reheat: You can easily reheat these potatoes in the microwave on high for 30 seconds to 1 minute at a time. You can add a bit of extra half and half when reheating if you like.