Sweet Onion and Mashed Potato Bake

Indulge in comfort food perfection with this Sweet Onion and Mashed Potato Bake, a creamy, cheesy casserole that’s packed with layers of rich flavor. Fluffy, buttery mashed potatoes are combined with caramelized sweet onions and topped with a decadent blend of Parmesan and cheddar cheeses, creating a golden, bubbly crust that’s hard to resist. This oven-baked dish is perfect for family dinners, potlucks, or holiday celebrations, offering a delicious twist on traditional mashed potatoes. Featuring simple ingredients like russet potatoes, milk, heavy cream, and savory seasonings, this recipe provides the ultimate balance of creamy, savory, and slightly sweet flavors, all while being easy to prepare. Serve it warm, garnished with fresh parsley for a touch of color and freshness, and watch it become a new household favorite.

Nutriscore Rating: 68/100

Prep Time:20 mins

Cook Time:60 mins

Total Time:80 mins

Servings: 6

Ingredients

• 6 large russet potatoes
• 2 large sweet onions
• 6 tablespoons unsalted butter
• 1 cup milk
• 0.5 cup heavy cream
• 2 teaspoons salt
• 1 teaspoon ground black pepper
• 0.5 teaspoon garlic powder
• 0.5 cup grated Parmesan cheese
• 1 cup shredded cheddar cheese
• 2 tablespoons olive oil
• 2 tablespoons fresh parsley (optional, for garnish)

Directions

Step 1

Peel and dice the russet potatoes into even-sized chunks. Place them in a large pot of salted water and bring to a boil. Cook for 15-20 minutes, or until fork-tender.

Step 2

While the potatoes cook, peel and thinly slice the sweet onions. Heat the olive oil in a skillet over medium heat. Add the onions and a pinch of salt, cooking them slowly for 15-20 minutes until golden and caramelized. Set aside.

Step 3

Drain the cooked potatoes and return them to the pot. Add 4 tablespoons of butter, the milk, and the heavy cream. Mash until smooth and creamy. Stir in 1 teaspoon of salt, the black pepper, and garlic powder. Taste and adjust seasonings if needed.

Step 4

Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with 1 tablespoon of butter.

Step 5

Spread half of the mashed potatoes evenly onto the bottom of the baking dish. Layer the caramelized onions on top of the mashed potatoes. Spread the remaining mashed potatoes over the onions, smoothing the top.

Step 6

Melt the remaining 1 tablespoon of butter and mix it with the grated Parmesan cheese. Sprinkle this mixture evenly over the top of the dish, followed by the shredded cheddar cheese.

Step 7

Bake in the preheated oven for 25-30 minutes, or until the top is golden and bubbly.

Step 8

Remove from the oven and let cool for 5 minutes. Garnish with fresh parsley if desired, then serve warm.

Nutrition Facts

Serving size	(2846.1g)

Amount per serving	% Daily Value*
Calories	3913.9

Total Fat 194.0g	0%
Saturated Fat 105.7g	0%
Polyunsaturated Fat 2.8g
Cholesterol 489.0mg	0%
Sodium 6541.9mg	0%
Total Carbohydrate 451.2g	0%
Dietary Fiber 38.8g	0%
Total Sugars 52.8g
Protein 109.9g	0%

Vitamin D 107.4IU	0%
Calcium 1948.0mg	0%
Iron 22.6mg	0%
Potassium 11111.8mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 43.8%

Protein: 11.0%

Carbs: 45.2%