Caramelized Onion and Horseradish Mashed Potatoes

Ingredients

• 1/4 cup butter, divided
• 4 cups chopped onion
• 2 teaspoons brown sugar
• 1 tablespoon white balsamic vinegar (optional)
• 2 1/2 pounds cubed peeled baking potato
• 1/2 cup whole milk
• 1/4 cup Dijon mustard
• 1 tablespoon fresh lemon juice
• 2 tablespoons prepared horseradish
• 1 tablespoon light mayonnaise
• 1/2 teaspoon salt

Preparation

1. Melt 1 tablespoon butter in a medium nonstick skillet over medium-high heat. Add onion and sugar; sauté 10 minutes or until caramelized. Remove from heat; stir in vinegar, if desired.
2. Place potato in a saucepan, and cover with water. Bring to a boil. Reduce heat; simmer 15 minutes or until tender.
3. Drain and return potato to pan. Add 3 tablespoons butter and milk; mash to desired consistency. Cook 2 minutes or until thoroughly heated, stirring constantly.
4. Combine Dijon mustard and remaining ingredients in a small bowl, stirring with a whisk until blended. Add Dijon mustard mixture and caramelized onion mixture to potato mixture, stirring to combine.