There is something truly magical about the way sweet, golden caramelized onions weave their rich, buttery flavor into creamy mashed potatoes, transforming a humble side dish into a show-stopping delight. This Caramelized Onion Mashed Potatoes Recipe brings together the perfect balance of silkiness, savory depth, and cheesy warmth, making it a dish you’ll want to serve not only during special occasions but as a comforting weeknight treat. Whether you’re a seasoned cook or just diving into the world of elevated comfort food, this recipe promises to impress your taste buds and your loved ones alike.
Ingredients You’ll Need
Gathering simple, high-quality ingredients is the secret to nailing this Caramelized Onion Mashed Potatoes Recipe. Each component plays a crucial role — from the caramelized onions that add sweetness and depth, to the creamy half and half that makes the potatoes ultra-lush, and the gruyere cheese that delivers a subtle nutty finish.
- Olive oil: A healthy fat that starts the caramelization process, adding richness and helping to cook the onions evenly.
- Unsalted butter: Adds silkiness to both the onion caramelization and the mashed potatoes, enhancing flavor without overpowering.
- Yellow onions: The star ingredient for caramelization, their natural sugars become perfectly sweet and golden brown over slow cooking.
- Kosher salt: Essential for seasoning at multiple stages, bringing out the natural flavors of the onions and potatoes.
- Russet potatoes: Ideal for mashing because of their fluffy texture when cooked, creating a smooth base for the dish.
- Garlic cloves: Gently cooked with the potatoes to infuse subtle aromatic warmth into every bite.
- Half and half: Provides creaminess without being too heavy, balancing the texture perfectly.
- Black pepper: Freshly ground adds just the right amount of spice to complement the sweetness.
- Gruyere cheese: Offers a delicate nuttiness and melts beautifully into the mash for a luscious finish.
- Chives and fresh thyme: Bright, fresh herbs that add a pop of color and an herbal complexity when sprinkled on top.
How to Make Caramelized Onion Mashed Potatoes Recipe
Step 1: Caramelize the Onions to Perfection
Begin by heating olive oil and butter in a large pan over medium-low heat. Add thinly sliced yellow onions and a pinch of kosher salt, then cover the pan. This slow cooking step requires patience, but it’s worth every minute — stir the onions every 5 minutes or so as they gradually transform into a rich, golden brown harmony of sweet and savory flavors. This process typically takes 30 to 40 minutes. The deep caramelization is what elevates this mashed potato recipe from ordinary to extraordinary.
Step 2: Cook the Potatoes with Garlic
While the onions caramelize, prepare the potatoes. Place peeled and diced russet potatoes into a large pot, along with smashed garlic cloves and a pinch of salt. Cover with cold water and bring to a boil. Cook until the potatoes are fork tender, approximately 15 to 20 minutes. Drain completely once done, ensuring no excess water remains, so your mashed potatoes remain creamy and not watery.
Step 3: Mash and Mix
Return the drained potatoes and garlic to the warm pot. Use a potato masher or hand mixer to mash until smooth. Add the remaining salt, butter, half and half, and black pepper. Continue mashing or mixing until the potatoes reach a luscious, creamy consistency. Now, fold in half of the caramelized onions and all of the grated gruyere cheese, distributing those wonderful flavors evenly throughout the mash. If desired, add a splash more half and half for an even silkier texture. Taste and adjust seasoning to your preference.
Step 4: Final Touch and Presentation
Transfer the mashed potatoes to a serving dish. Top with the remaining caramelized onions, a sprinkle of grated gruyere, fresh chives, thyme, and a small pat of butter to melt on top just before serving. These finishing touches not only enhance visuals but also add layers of flavor that make every bite memorable.
How to Serve Caramelized Onion Mashed Potatoes Recipe
Garnishes
Simple yet impactful garnishes can elevate your presentation. Thinly sliced chives lend a fresh pop of green and a delicate onion flavor, while sprigs of fresh thyme introduce fragrant earthiness. A final sprinkle of grated gruyere cheese encourages melty pockets of gooey goodness that melt right into the warm potatoes on the plate. Butter curls on top add a glossy, inviting finish.
Side Dishes
This Caramelized Onion Mashed Potatoes Recipe pairs beautifully with roasted meats like herb-crusted chicken, glazed ham, or a perfectly seared steak. The creamy texture and sweet-savory profile offer a welcome contrast to protein-rich dishes and roasted vegetables. For a vegetarian spread, serve alongside sautéed mushrooms or a hearty lentil stew.
Creative Ways to Present
Get creative by piping the mashed potatoes into elegant swirls using a piping bag fitted with a large star tip. Place dollops in individual ramekins or serve family-style in a beautiful ceramic bowl garnished with your favorite fresh herbs. You can also drizzle a touch of browned butter or a drizzle of truffle oil over the finished dish for an indulgent twist that will wow your guests.
Make Ahead and Storage
Storing Leftovers
If you find yourself with leftovers, store them in an airtight container in the refrigerator. Caramelized Onion Mashed Potatoes stay beautifully creamy and flavorful for up to 4 days, making them perfect for meal prep or a quick reheat on busy days.
Freezing
This recipe freezes well for future enjoyment. Transfer the cooled mashed potatoes to a freezer-safe container or heavy-duty resealable bag. Freeze for up to two months. When ready to enjoy, thaw overnight in the refrigerator for best results.
Reheating
Reheat gently on the stove over low heat, adding a splash of half and half or milk to restore creaminess as it warms. Stir often to prevent sticking. You can also reheat in the microwave in short bursts, stirring between intervals to ensure even heat distribution without drying out the potatoes.
FAQs
Can I use other types of potatoes for this recipe?
While russet potatoes are preferred due to their fluffiness, Yukon Golds can also work well. They have a naturally buttery texture but may make the mash slightly denser.
How long does it take to caramelize the onions?
Patience is key! It usually takes about 30 to 40 minutes over medium-low heat, stirring often, to develop the rich, deep brown color and sweet flavor that defines caramelized onions.
Can this recipe be made dairy-free?
Yes! Substitute the butter with a plant-based alternative and use coconut milk or a dairy-free creamer instead of half and half. For cheese, try a vegan cheese substitute or omit it altogether.
Will the potatoes be too sweet with the caramelized onions?
The sweetness of the onions balances beautifully with the savory elements like garlic, cheese, and black pepper, resulting in a harmonious blend rather than an overly sweet dish.
Can I prepare the caramelized onions ahead of time?
Absolutely! You can caramelize the onions up to 3 days in advance and store them in the refrigerator. This makes assembling the mashed potatoes quicker on the day you plan to serve.
Final Thoughts
This Caramelized Onion Mashed Potatoes Recipe is a comforting, indulgent take on a classic side dish that’s sure to become a favorite at your table. Its rich, creamy texture and vibrant, layered flavors showcase how simple ingredients prepared thoughtfully can create extraordinary results. Give it a try and watch it quickly become your go-to recipe for everything from holidays to cozy weeknights.
Print
Caramelized Onion Mashed Potatoes Recipe
- Prep Time: 15 minutes
- Cook Time: 50 minutes
- Total Time: 1 hour 5 minutes
- Yield: 8 servings
- Category: Side Dish
- Method: Stovetop
- Cuisine: American
- Diet: Vegetarian
Description
These Caramelized Onion Mashed Potatoes are a rich and creamy twist on the classic mashed potato side dish. Featuring deeply caramelized onions, melted gruyere cheese, and a smooth blend of butter and half-and-half, they deliver a perfect balance of savory and sweet flavors. Ideal for holiday dinners or elevating any weeknight meal, this recipe combines comfort with elegance in every bite.
Ingredients
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 over medium-low heat. Add 2 tablespoons olive oil and 1 tablespoon butter. Stir in the sliced onions and sprinkle 1/4 teaspoon kosher salt over them. Cover and cook for 30-40 minutes, stirring every 5 minutes until the onions turn a deep caramelized golden brown.
- Cook the Potatoes: Place diced potatoes, smashed garlic, and 1 teaspoon kosher salt into a large pot. Cover with cold water and bring to a boil. Cook until the potatoes are fork tender, about 15-20 minutes. Drain well.
- Mash the Potatoes: Return drained potatoes and garlic to the warm pot. Mash using a potato masher or hand mixer until smooth.
- Add Ingredients to Potatoes: Blend in the remaining 1 teaspoon kosher salt, 4 tablespoons unsalted butter, half and half, and black pepper. Mash until creamy and fully combined.
- Incorporate Onions and Cheese: Fold half of the caramelized onions and all of the grated gruyere cheese into the mashed potatoes until well combined. Add more half and half if needed for creaminess. Adjust salt and pepper to taste.
- Serve: Transfer mashed potatoes to a serving dish. Top with the remaining caramelized onions, additional grated gruyere, thinly sliced chives, fresh thyme, and a pat of butter before serving.
Notes
- Use russet potatoes for the best texture and creaminess in mashed potatoes.
- Caramelize onions slowly over low heat to avoid burning and develop deep sweetness.
- Gruyere cheese adds a nutty, creamy flavor that melts beautifully into the potatoes.
- For extra creaminess, adjust the amount of half and half to your liking.
- Leftovers can be refrigerated for up to 3 days and reheated gently with a splash of half and half.
