- 8
- 25 mins
- 50 mins
Ingredients
- 1 1/2 tablespoons butter
- 2 onions, sliced and separated into rings
- 1/2 tablespoon white wine vinegar
- 1/4 teaspoon ground dried thyme
- 3 large baking potatoes, peeled and cubed
- 1/2 tablespoon Dijon mustard
- 1 tablespoons prepared horseradish, or to taste
- Salt and cracked black pepper to taste
- 1/8 cup softened butter
- 1/2 to 2/3 cup half-and-half
Preparation
Step 1
Melt 1 1/2 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.
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. (Alternatively, you can bake the whole potatoes in the oven for about an hour at 400 degrees, allow to sit until cool enough to handle, scoop out potato into a large bowl and continue with recipe.)
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.