Bacon Horseradish Mashed Potatoes with Caramelized Onions
Creamy mashed russet potatoes enriched with caramelized onions, crispy bacon, and tangy horseradish. Dijon mustard and thyme add depth to this side dish, balanced with half-and-half and butter for richness. The vinegar-spiked onions cook low and slow until deep brown.
Ingredients
- 2 onions, diced
- 1 tablespoon De Nigris white wine vinegar
- ½ teaspoon ground dried thyme
- 6 large russet potatoes, peeled and cubed
- 1 tablespoon Dijon mustard
- 2 tablespoons prepared horseradishfresh grated horseradish1:1 by volume, or less if milder result desiredcondiment
horseradish potency varies; fresh will be sharper
Full guide → - salt
- cracked black pepper
- ¼ cup softened butter
- ¾ cup half-and-halfheavy cream1:1dairyadds dairy
richer result
- ½ pound bacon, cooked, drained and chopped
Instructions
- 1
Melt butter in a large skillet over medium-high heat. Add diced onions and cook for 5 minutes.
- 2
Reduce heat to medium and continue cooking, stirring frequently, until onions are soft and deep brown, 15 to 25 minutes.
- 3
Stir in vinegar and thyme, cook for 5 minutes more.
- 4
Meanwhile, place cubed potatoes in a large pot and cover with salted water. Bring to a boil.
- 5
Reduce heat to medium-low, cover, and simmer until potatoes pierce easily with a fork, about 20 minutes.
- 6
Drain potatoes in a colander and steam for 1 minute.
- 7
Transfer potatoes to a serving bowl. Mash with Dijon mustard, horseradish, salt, and cracked black pepper until smooth.
- 8
Mix in softened butter, caramelized onions, and half-and-half until onions are evenly distributed.
Tips
Caramelize onions low and slow for maximum depth of flavor. Do not rush this step.
Steam potatoes briefly after draining to ensure they are dry, which helps them mash smoothly.
Add horseradish gradually, tasting as you go, since heat varies by brand.
Good to Know
Refrigerate in an airtight container up to 3 days. Reheat gently on stovetop with additional half-and-half if needed.
Prepare potatoes and caramelized onions up to 1 day ahead. Cook bacon ahead. Assemble and mash just before serving for best texture.
Serve hot as a side dish. Top with additional crispy bacon if desired.
Common Mistakes
Do not skip the steaming step after draining potatoes; wet potatoes will result in gluey mashed potatoes.
Do not rush the onion caramelization; low heat for 15-25 minutes develops the deep brown color and complex flavor.
Do not over-mash; some lumps are acceptable and preferable to gluey texture.
Substitutions
Dairy-Free Swaps
General Alternatives
horseradish potency varies; fresh will be sharper
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