Caramelized Onion Gratin Potatoes
A comforting dish combining sweet, caramelized onions with hearty potatoes, all enveloped in a creamy, cheesy layer.
Ingredients
Main Ingredients
- 4 large large russet potatoes A sturdy variety that holds up beautifully.
- 2 large large onions Sweet onions like Vidalia work wonderfully.
- 2 cups shredded Gruyère cheese For that nutty richness; feel free to swap with cheddar if preferred!
- 1 cup heavy cream You can substitute with half-and-half for a lighter version.
- 2 tablespoons butter Adds depth and richness; using olive oil offers a lighter twist.
- to taste Salt and pepper Always a trusty duo in any recipe.
- to taste Fresh thyme or rosemary Optional; a sprinkle of herbs provides fragrant notes.
Instructions
Preparation
- Preheat the oven to 375°F (190°C).
- In a large skillet over medium heat, melt 2 tablespoons of butter. Add the sliced onions and sprinkle with a pinch of salt. Cook for about 20-25 minutes until the onions turn golden brown.
- While the onions are caramelizing, wash the russet potatoes thoroughly and slice them thinly (about 1/8 inch thick) using a sharp knife or mandolin.
Assembly
- In a greased baking dish, create a base layer with half of the sliced potatoes, slightly overlapping them. Season with salt and pepper.
- Follow with half of the caramelized onions, and sprinkle a generous cup of Gruyère cheese over the top.
- Repeat layers with the remaining potatoes and onions, finishing off with the other cup of Gruyère cheese on top.
Baking
- Gently pour the heavy cream over the entire dish.
- Cover the dish with aluminum foil and place it in the oven. Bake for 40 minutes, then remove the foil and bake for an additional 20 minutes until the top is bubbly and golden brown.
Serving
- Let the gratin cool for a few minutes before serving.
Notes
For variations, consider adding sautéed greens or substituting cheeses as desired. Store leftovers in an airtight container for up to 3 days, or freeze for up to a month.