Caramelized Onion and Horseradish Smashed Potatoes

Caramelized Onion and Horseradish Smashed Potatoes

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"Caramelized onions give this incredible side dish a subtle sweetness, and the addition of horseradish gives it a little attitude! They make an absolutely fabulous side dish to prime rib, and have become a tradition every year at family holiday gatherings! To save time, the caramelized onions can be made ahead of time and refrigerated, then warmed before adding to the potatoes."
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50 m servings 381 cals
Serving size has been adjusted!

Original recipe yields 8 servings



  • Calories:
  • 381 kcal
  • 19%
  • Fat:
  • 13.1 g
  • 20%
  • Carbs:
  • 60.8g
  • 20%
  • Protein:
  • 7.7 g
  • 15%
  • Cholesterol:
  • 35 mg
  • 12%
  • Sodium:
  • 209 mg
  • 8%

Based on a 2,000 calorie diet

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Nutritional Information

1 Serving
Servings Per Recipe:
Amount Per Serving
  • * Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
  • ** Nutrient information is not available for all ingredients. Amount is based on available nutrient data.
  • (-) Information is not currently available for this nutrient. If you are following a medically restrictive diet, please consult your doctor or registered dietitian before preparing this recipe for personal consumption.

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  1. Melt 3 tablespoons butter in a large skillet over medium-high heat. Add the onions and cook for 5 minutes. Reduce heat to medium, and continue cooking, stirring frequently, until the onions have softened, and achieved a deep brown color, 15 to 25 minutes. Stir in vinegar and thyme, and cook for 5 minutes more.
  2. While the onions are cooking, place cubed potatoes in large pot and cover with salted water. Bring to a boil, then reduce heat to medium-low, cover, and simmer until the potatoes can be pierced easily with a fork, about 20 minutes. Drain the potatoes in a colander, and allow to steam for a minute.
  3. To finish the dish, transfer the potatoes to a serving bowl, and use a potato masher to mix with Dijon mustard, horseradish, salt and cracked black pepper until smooth. Mix in softened butter, caramelized onions, and half-and-half until onions are distributed evenly.


  1. 91 Ratings

Most helpful positive review

We loved these potatoes! Beautiful rich color from the caramelized onions and deeply flavored. Definitely worth the extra effort and time it took to caramelize the onions. Just enough horseradi...

Most helpful critical review

Not very good at all!!! Will not make again

We loved these potatoes! Beautiful rich color from the caramelized onions and deeply flavored. Definitely worth the extra effort and time it took to caramelize the onions. Just enough horseradi...

Fantastic recipe! I added a couple of cloves of fresh roasted garlic, but add garlic to almost everything. I also added in a couple of dashes of white pepper!

This side dish was great - my family (kids, too!) liked it...a nice flavor with a little tang, but not too much for those who don't like spice. It didn't take too long to make and didn't have a...

This recipe is fantastic! The only change I made was to substitute the white wine vinegar to half white cooking wine, half cider vinegar, because I didn't have white wine vinegar on hand. For th...

I thought this was really delicious. When I went to make it I found I had only 1 rather elderly potato. So I made instant mashed and added the seasonings. It was great and my guest had no idea...

Yummy side dish! I did have to add more 1/2 & 1/2 to make it creamy enough and also a bunch more horseradish, because we like spicy! :)

very yummy. i scaled back to 6 servings, and even opted to use 2 sweet vidalia onions over the 3 they suggested. it was plenty!!! also diced for ease of mixing and eating. omitted thyme since i...

Wonderful, wonderful wonderful potatoes. Made these for a dinner party to serve under Beef Burgundy. Simple, easy, tasty, full flavored. I did use Yukon Gold potatoes instead of russets, because...

Very nice twist on regular mashed potatoes. I omitted the horseradish (I forgot it), and all 5 of us loved it. Would suggest that the onions are cut up more than just 'sliced into rings' because...