Horseradish Mashed Potatoes With Caramelized Onions

READY IN: 1hr 20mins
Recipe by lazyme

From Bon Appetit, a nice side dish that can be made ahead. ZWT West region (Idaho potatoes).

Top Review by sassafrasnanc

Loved this recipe! We enjoyed the sweetness of the carmelized onions with the strong flavor of the horseradish! Served this with "Recipe #305341" for a totally German dinner! Also served a cucumber salad with this dinner. ZWT4.

Ingredients Nutrition

  • 14 cup butter
  • 2 14 lbs white onions, thinly sliced
  • 3 tablespoons balsamic vinegar
  • 2 teaspoons fresh thyme, chopped
  • 3 12 lbs russet potatoes, peeled, cut into 1-inch pieces
  • 7 tablespoons whole milk
  • 14 cup prepared horseradish
  • 6 tablespoons butter


  1. Melt 1/4 cup butter in large skillet over medium heat. Add onions; saute until deep golden, about 30 minutes. Add vinegar and thyme. Reduce heat to low; saute 4 minutes. Season with salt and paper.
  2. Meanwhile, cook potatoes in large pot of boiling salted water until very tender, about 20 minutes. Drain. Return to same pot; mash until smooth. Add 6 tablespoons milk, horseradish and 6 tablespoons butter; stir to blend. Thin with 2 tablespoons milk if necessary. Add 1 to 2 tablespoons more butter if necessary. Season with salt and pepper.
  3. Transfer potatoes to serving dish. Spoon onion mixture atop potatoes. (Can be prepared 8 hours ahead. Cover with foil and refrigerate. Rewarm in 350ºF oven about 30 minutes). Serve hot.

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