Cheesy Caramelized Onion Mashed Potato Bake

5 stars

Cheesy Caramelized Onion Mashed Potato Bake

Make mashed potatoes that your friends and family will go crazy for! Made with caramelized onions, lots of cheese, and a "secret" ingredient that takes the flavor to another level! Topped with parmesan breadcrumbs and baked until hot and melty. This fun side dish can even be made ahead of time!

Prep Time20

Cook Time1 15

Total Time1 35

Course: Dinner

Cuisine: American

Servings: servings

Calories: 712kcal

Author: Rachel Kochlin

Equipment

Ingredients

2 yellow onions thinly sliced
¾ cup salted butter divided
5 pounds Yukon Gold or russet potatoes
1 tablespoon + 1 teaspoon salt
1 cup heavy cream
8 ounces French onion dip (1 cup)
2 cups gruyere cheese shredded
1 cup swiss cheese shredded

Parmesan Herb Breadcrumbs

8 ounces crusty bread torn into small pieces (4-5 cups)
½ cup parmesan cheese grated
¼ cup olive oil
¼ teaspoon salt

Instructions

Melt 4 tablespoons of butter and the onions to a skillet over medium heat. Cook for about 10 minutes until the onions soften. Reduce heat to medium-low and continue to cook another 40-50 minutes, stirring occasionally, until the onions are very soft, golden brown and caramelized. If the onions start to stick to the skillet and are cooking too quickly, reduce to low heat.
Meanwhile, prepare the potatoes by peeling and cutting into quarters. Add the potatoes to a large pot with 1 tablespoon of salt and cover with water. Bring to a boil and cook for 20-30 minutes until the potatoes are fork tender, then drain.
Preheat the oven to 375°F.
Using the same pot, heat together the remaining 8 tablespoons of butter, heavy cream, and 1 teaspoon salt on the stove over medium heat until the butter is melted. Remove from heat and add the potatoes, caramelized onions, french onion dip, and half the cheese. Mash with a potato masher until smooth. Transfer the potatoes to a 9x13 inch baking dish.
Pulse the bread in a food processor until crumbly. Transfer to a bowl and toss with the parmesan cheese, olive oil and salt. Spread the bread crumbs on a parchment lined baking sheet and bake for 10 minutes until golden brown.
Top the potatoes with the remaining cheese and bread crumbs.
Cover and bake for 30 minutes, then uncover and continue to bake another 10-15 minutes until the breadcrumbs are golden brown and the cheese is melted.

Nutrition