Description
Creamy potato casserole layered with caramelized onions, Parmesan, and fresh thyme. Perfect for cozy dinners or holiday meals.
Ingredients
- 2 tablespoons unsalted butter
- 2 large yellow onions, thinly sliced
- 1 teaspoon granulated sugar (optional)
- 1 tablespoon olive oil (optional)
- 2 cups heavy cream
- 1 cup finely grated Parmesan cheese, plus 2 tablespoons for topping
- 1 1/2 teaspoons kosher salt, divided
- 1 teaspoon freshly ground black pepper
- 2 teaspoons fresh thyme leaves, chopped (or 1 teaspoon dried thyme)
- 3 pounds russet or Yukon Gold potatoes, peeled and thinly sliced
- 1 tablespoon unsalted butter or cooking spray for greasing the dish
Instructions
- Melt 2 tablespoons butter in a skillet over medium heat. Add onions and sugar (optional). Cook, stirring occasionally, until golden brown (15–20 minutes). Drizzle olive oil if onions appear dry.
- In a saucepan, combine heavy cream, 1 cup Parmesan, 1 teaspoon salt, black pepper, and thyme. Heat gently until smooth and creamy.
- Grease a glass casserole dish with butter or cooking spray. Layer sliced potatoes, sprinkle with salt, and add caramelized onions. Repeat until all potatoes and onions are used.
- Pour the cream mixture evenly over the layers. Sprinkle remaining 2 tablespoons Parmesan on top. Cover with foil.
- Bake at 375°F (190°C) for 45 minutes. Remove foil and bake 15–20 more minutes until golden and bubbly.
- Rest 10–15 minutes before slicing and serving.
Notes
- For extra flavor, sprinkle smoked paprika or add cooked bacon between layers.
- Slice potatoes thinly for even cooking.
- Casserole can be made ahead; refrigerate and bake the next day.
- Prep Time: 20 minutes
- Cook Time: 60 minutes