Mashed Potato Gratin With Garlic & Onions

Servings: 6 Difficulty: Intermediate
Creamy, roasted garlic and onion mashed potatoes baked into a golden, bubbly gratin.
Mashed Potato Gratin With Garlic & Onions recipe image

Mashed Potato Gratin With Garlic & Onions

Difficulty: Intermediate
Servings: 6 Calories: 426.5

Description

This luxurious side dish elevates humble potatoes into a decadent feast. By roasting whole garlic heads and onions first, you unlock deep, sweet caramelized flavors that infuse the creamy mash. The potatoes are mashed until silky, then combined with the soft roasted vegetables and a touch of heavy cream before being topped with Gruyere cheese. Baked until golden and bubbling, this gratin offers a rich, comforting texture with every bite. It pairs beautifully with roasted meats or stands alone as a hearty vegetarian main. Perfect for holiday dinners, cozy weeknight meals, or potlucks where you want to impress with homemade comfort food.

Ingredients

Directions

  1. Preheat oven to 425&# 194;°F (220ðC).
  2. Remove papery outer layers from garlic heads but keep cloves intact. Wrap tightly in foil.
  3. Place onions on a double sheet of foil without wrapping. Place potatoes directly on the oven rack, piercing each several times with a fork.
  4. Roast garlic for 1 hour. Roast onions and potatoes for 1 hour and 15 minutes, or until soft and tender.
  5. Remove garlic from oven, unwrap, and let cool for 5 minutes. Squeeze roasted garlic cloves from their skins into a large bowl.
  6. Remove potatoes from oven. Cut lengthwise and squeeze open to scoop the flesh into the bowl with the garlic. Mash thoroughly.
  7. Peel roasted onions, removing skins and first layer. Trim ends and puree onions in a food processor until smooth. Add to potato mixture.
  8. Add 1/4 cup heavy cream, salt, and pepper to the bowl. Beat with a mixer using the paddle attachment until smooth and fully blended.
  9. Transfer the mixture to a large gratin dish. Sprinkle the top evenly with grated Gruyere cheese.
  10. Reduce oven temperature to 350ðF (175ðC).
  11. Pour the remaining 1 cup of heavy cream over the potato mixture.
  12. Bake uncovered for 40-50 minutes, until the top is golden brown, bubbly, and the cream has thickened.

Nutrition Facts

Servings 6


Amount Per Serving
Calories 426.5kcal
% Daily Value *
Total Fat 27.4g43%
Saturated Fat 16.6g83%
Cholesterol 82.5mg28%
Sodium 23.2mg1%
Total Carbohydrate 40.0g14%
Dietary Fiber 4.1g17%
Sugars 5.3g
Protein 7.3g15%

* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.

Note

Make Ahead: This dish can be prepared up to the point of adding the final cream and cheese, then covered and refrigerated for up to a day. Let it come to room temperature before baking.

Storage: Leftovers keep well in the refrigerator for 3-4 days. This gratin is excellent served cold or reheated.

Ingredient Tip: Ensure onions are completely soft and almost collapsed before removing from the oven; add a few more minutes if needed for best puree consistency.

Variation: For a crispier top, broil for the last 2-3 minutes of baking, watching carefully to prevent burning.

Keywords: potato gratin, roasted garlic, baked onions, mashed potatoes, gruyere cheese, comfort food, vegetarian dinner, heavy cream, idaho potatoes, garlic mash, onion gratin, holiday side dish, creamy potatoes, baked potato dish, garlic lovers, family dinner, easy gratin, roasted vegetables, cheese gratin, winter comfort
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