Name: Easy Caramelized Onion Mashed Potatoes
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: American
Ingredients: 2 pounds Yukon Gold or Russet potatoes, peeled and cubed; 2 tablespoons unsalted butter (for the onions); 1 tablespoon olive oil; 2 large yellow onions, thinly sliced; 1/4 teaspoon salt (for onions); 1/2 cup whole milk or heavy cream; 4 tablespoons unsalted butter (for the mash); Salt and pepper to taste; Optional: chopped chives or parsley for garnish

Creamy mashed potatoes are already a comfort food favorite, but when you add deeply golden, sweet caramelized onions into the mix? Pure magic. This recipe takes your classic mashed potatoes up a few notches, transforming them into a savory side dish that’s perfect for holiday feasts, cozy family dinners, or anytime you need a little indulgence on your plate.

The onions cook down slowly, developing a mellow sweetness that pairs beautifully with buttery, fluffy potatoes. Each bite delivers layers of flavor, with the familiar richness of mashed potatoes balanced by the deep umami of the caramelized onions. If you’re looking for a side dish that steals the spotlight, this one delivers.

What Kind of Potatoes Should I Use?

Yukon Golds are ideal for mashed potatoes with a rich texture and buttery flavor, but Russets also work if you prefer something fluffier. Just be sure to avoid waxy varieties like red potatoes, which can become gluey when mashed.

Ingredients for the Easy Caramelized Onion Mashed Potatoes

2 pounds Yukon Gold or Russet potatoes, peeled and cubed
2 tablespoons unsalted butter (for the onions)
1 tablespoon olive oil
2 large yellow onions, thinly sliced
1/4 teaspoon salt (for onions)
1/2 cup whole milk or heavy cream
4 tablespoons unsalted butter (for the mash)
Salt and pepper to taste
Optional: chopped chives or parsley for garnish

Easy Caramelized Onion Mashed Potatoes (1)

How To Make the Easy Caramelized Onion Mashed Potatoes

Step 1: Caramelize the Onions

In a large skillet over medium heat, melt 2 tablespoons of butter with the olive oil. Add sliced onions and 1/4 teaspoon of salt. Cook slowly, stirring occasionally, for 30-40 minutes until the onions are deeply golden and caramelized. If they start to brown too fast, lower the heat. Set aside.

Step 2: Cook the Potatoes

Place the peeled and cubed potatoes in a large pot and cover with cold water. Add a generous pinch of salt. Bring to a boil, then reduce to a simmer. Cook for 15-20 minutes or until fork tender. Drain well.

Step 3: Mash the Potatoes

Return the drained potatoes to the pot or a mixing bowl. Add 4 tablespoons of butter and the warmed milk or cream. Mash until smooth and fluffy, adjusting the milk quantity as needed for your desired consistency.

Step 4: Combine and Season

Stir in the caramelized onions, making sure they’re evenly distributed throughout the mashed potatoes. Taste and season with salt and freshly cracked black pepper.

Step 5: Serve

Transfer to a serving bowl, garnish with herbs if desired, and serve warm.

Serving and Storing Easy Caramelized Onion Mashed Potatoes

This dish is best served hot and fresh, ideally with mains like roasted meats or holiday favorites. For make-ahead ease, you can prepare the caramelized onions up to 3 days in advance and refrigerate them.

Store any leftover mashed potatoes in an airtight container in the fridge for up to 4 days. To reheat, add a splash of milk and rewarm gently on the stove or in the microwave, stirring occasionally.

Frequently Asked Questions

How do I caramelize onions faster?

Low and slow is best, but if you’re short on time, adding a pinch of sugar can speed things up a little. Just keep an eye on them so they don’t burn.

Can I use plant-based alternatives?

Absolutely! Use vegan butter and your favorite non-dairy milk like oat or almond. The result is still silky and flavorful.

What herbs pair well with this dish?

Fresh thyme, chives, or parsley add brightness that contrasts beautifully with the richness of the onions and potatoes.

Can I freeze the leftovers?

Freezing mashed potatoes can change their texture, but it’s doable. Reheat with extra cream or milk and stir until creamy again.

Is it okay to use red onions?

Yellow onions are best for sweetness and depth of flavor, but red onions work in a pinch—they’ll just give a slightly different flavor profile.

Want More Side Dish Ideas?

If these creamy, onion-packed potatoes are calling your name, take a look at some more cozy and comforting sides from Nina Dishes:

📌 Save this recipe to your Pinterest board for your next dinner party or family gathering.

Have you tried adding roasted garlic or maybe a sprinkle of Parmesan? Let me know how yours turned out in the comments. Everyone has their own twist, and I love hearing yours!

Want more comforting dishes like this? Head over to my Pinterest page where I share new recipes daily!

Easy Caramelized Onion Mashed Potatoes

Author: Nina Klatten
Total Time: 55 minutes
Yield: 6 servings
Diet: Vegetarian

Print Recipe

Description

Creamy, buttery mashed potatoes get a major upgrade with sweet, golden caramelized onions. Perfect for holiday meals or comfort food dinners, this savory side dish is loaded with flavor and warmth.

Ingredients

2 pounds Yukon Gold or Russet potatoes, peeled and cubed

2 tablespoons unsalted butter (for the onions)

1 tablespoon olive oil

2 large yellow onions, thinly sliced

1/4 teaspoon salt (for onions)

1/2 cup whole milk or heavy cream

4 tablespoons unsalted butter (for the mash)

Salt and pepper to taste

Optional: chopped chives or parsley for garnish

Instructions

1. In a large skillet over medium heat, melt 2 tablespoons of butter with the olive oil. Add sliced onions and 1/4 teaspoon of salt. Cook slowly, stirring occasionally, for 30-40 minutes until the onions are deeply golden and caramelized. Set aside.

2. Place the peeled and cubed potatoes in a large pot and cover with cold water. Add a generous pinch of salt. Bring to a boil, then reduce to a simmer. Cook for 15-20 minutes or until fork tender. Drain well.

3. Return the drained potatoes to the pot or a mixing bowl. Add 4 tablespoons of butter and the warmed milk or cream. Mash until smooth and fluffy.

4. Stir in the caramelized onions until evenly combined. Season with salt and black pepper to taste.

5. Transfer to a serving bowl, garnish with herbs if using, and serve warm.