French Onion Mashed Potatoes Recipe
French Onion Mashed Potatoes combine the creamy, buttery goodness of traditional mashed potatoes with the rich, savory flavor of French onion soup. This comforting side dish is perfect for holiday dinners, family gatherings, or any occasion where you want to impress your guests. With caramelized onions and a hint of cheese, these mashed potatoes are sure to be a hit!
Ingredients List
- 2 pounds russet potatoes, peeled and cut into chunks
- 2 tablespoons unsalted butter
- 1 large onion, thinly sliced
- 1 tablespoon olive oil
- 1 teaspoon salt (divided)
- 1/2 teaspoon black pepper
- 1/2 cup sour cream
- 1/2 cup milk (or more for desired consistency)
- 1 cup shredded Gruyère cheese (or Swiss cheese)
- Fresh chives or parsley for garnish (optional)
Timing
Preparing French Onion Mashed Potatoes takes about 15 minutes for prep and 30 minutes for cooking.
Step-by-Step Instructions
Step 1: Cook the Potatoes
- Boil the Potatoes: In a large pot, add the peeled and chopped potatoes and cover them with cold water. Add 1/2 teaspoon of salt. Bring to a boil over high heat, then reduce to a simmer and cook for about 15-20 minutes, or until the potatoes are fork-tender.
- Drain and Set Aside: Once cooked, drain the potatoes and set them aside.
Step 2: Caramelize the Onions
- Heat Oil and Butter: In a large skillet over medium heat, add the olive oil and butter.
- Add Onions: Once the butter has melted, add the sliced onions and sprinkle with the remaining 1/2 teaspoon of salt. Cook, stirring occasionally, for about 15-20 minutes or until the onions are golden brown and caramelized. If they start to stick, you can add a splash of water to deglaze the pan.
Step 3: Mash the Potatoes
- Combine Ingredients: In a large mixing bowl, add the drained potatoes, caramelized onions, sour cream, milk, black pepper, and half of the Gruyère cheese.
- Mash: Use a potato masher or electric mixer to mash the potatoes until smooth and creamy. Adjust the milk to reach your desired consistency.
Step 4: Add Cheese and Serve
- Mix in Cheese: Stir in the remaining Gruyère cheese until melted and well combined.
- Garnish and Serve: Transfer the mashed potatoes to a serving dish, garnish with chopped chives or parsley if desired, and serve warm.

Nutritional Information
Here’s a quick glance at the nutritional profile of French Onion Mashed Potatoes (per serving, assuming 8 servings):
| Nutrient | Amount per Serving |
|---|---|
| Calories | 250 |
| Protein | 6g |
| Fat | 10g |
| Carbohydrates | 36g |
| Fiber | 2g |
Tips for Customization
- Cheese Variations: Feel free to experiment with different cheeses such as cheddar, fontina, or even blue cheese for a unique flavor.
- Herb Infusion: Add fresh herbs like thyme or rosemary to the onions while caramelizing for extra flavor.
- Make It Creamy: For an even creamier texture, you can add cream cheese or heavy cream instead of sour cream.
Storing Tips for the Recipe
French Onion Mashed Potatoes can be stored in an airtight container in the refrigerator for up to 3 days. Reheat gently in the microwave or on the stovetop, adding a splash of milk to restore creaminess.
Conclusion
French Onion Mashed Potatoes are a delicious twist on a classic side dish, bringing the rich flavors of French onion soup right to your dinner table. Creamy, cheesy, and packed with flavor, these mashed potatoes are sure to be a favorite among family and friends. Enjoy this comforting dish at your next meal!
FAQs
Can I make these mashed potatoes ahead of time?
Yes! You can prepare the mashed potatoes in advance and store them in the refrigerator. Reheat them before serving.
Can I use other types of potatoes?
Yes! While russet potatoes are ideal for mashing, you can also use Yukon Gold potatoes for a creamier texture.
How do I prevent the onions from burning while caramelizing?
Keep the heat on medium and stir the onions regularly. If they start to stick or burn, add a splash of water or broth to help deglaze the pan.
Print
French Onion Mashed Potatoes Recipe
- Total Time: 45 minutes
Ingredients
- 2 pounds russet potatoes, peeled and cut into chunks
- 2 tablespoons unsalted butter
- 1 large onion, thinly sliced
- 1 tablespoon olive oil
- 1 teaspoon salt (divided)
- 1/2 teaspoon black pepper
- 1/2 cup sour cream
- 1/2 cup milk (or more for desired consistency)
- 1 cup shredded Gruyère cheese (or Swiss cheese)
- Fresh chives or parsley for garnish (optional)
Instructions
Step 1: Cook the Potatoes
- Boil the potatoes: In a large pot, add the peeled and chopped potatoes and cover them with cold water. Add 1/2 teaspoon of salt. Bring to a boil over high heat, then reduce to a simmer and cook for about 15–20 minutes, or until the potatoes are fork-tender.
- Drain and set aside: Once cooked, drain the potatoes and set them aside.
Step 2: Caramelize the Onions
- Heat oil and butter: In a large skillet over medium heat, add the olive oil and butter.
- Add onions: Once the butter has melted, add the sliced onions and sprinkle with the remaining 1/2 teaspoon of salt. Cook, stirring occasionally, for about 15–20 minutes or until the onions are golden brown and caramelized. If they start to stick, you can add a splash of water to deglaze the pan.
Step 3: Mash the Potatoes
- Combine ingredients: In a large mixing bowl, add the drained potatoes, caramelized onions, sour cream, milk, black pepper, and half of the Gruyère cheese.
- Mash: Use a potato masher or electric mixer to mash the potatoes until smooth and creamy. Adjust the milk to reach your desired consistency.
Step 4: Add Cheese and Serve
- Mix in cheese: Stir in the remaining Gruyère cheese until melted and well combined.
- Garnish and serve: Transfer the mashed potatoes to a serving dish, garnish with chopped chives or parsley if desired, and serve warm.
- Prep Time: 15
- Cook Time: 30
