Layers of roasted potatoes, caramelized onions, and melted Gruyère cheese combine for a savory French-inspired side.
# What you'll need:
→ Potatoes
01 - 3.3 lbs Yukon Gold or russet potatoes, scrubbed and sliced 1/3 inch thick
02 - 2 tbsp olive oil
03 - 1/2 tsp kosher salt
04 - 1/4 tsp freshly ground black pepper
→ Caramelized Onions
05 - 3 large yellow onions, thinly sliced
06 - 2 tbsp unsalted butter
07 - 1 tbsp olive oil
08 - 1/2 tsp kosher salt
09 - 1 tsp fresh thyme leaves or 1/2 tsp dried thyme
10 - 1 tsp balsamic vinegar
→ Topping
11 - 7 oz Gruyère cheese, grated
12 - 1 oz Parmesan cheese, grated (optional)
13 - 2 tbsp chopped fresh parsley for garnish
# Method:
01 - Preheat oven to 425°F. Line a large baking sheet with parchment paper.
02 - Toss potato slices with olive oil, kosher salt, and black pepper. Arrange in a single layer on the prepared baking sheet. Roast for 25 to 30 minutes, flipping once halfway through, until golden and tender.
03 - While potatoes roast, heat butter and 1 tbsp olive oil in a large skillet over medium-low heat. Add sliced onions and salt. Cook, stirring frequently, for 25 to 30 minutes until deeply golden and caramelized. Stir in thyme and balsamic vinegar, cooking for another 1 to 2 minutes. Remove from heat.
04 - Reduce oven temperature to 400°F. Lightly grease a baking dish and arrange roasted potato slices with slight overlap.
05 - Evenly spoon caramelized onions over the layered potatoes. Sprinkle grated Gruyère and optional Parmesan cheese over the top.
06 - Bake for 10 to 15 minutes until cheese melts and bubbles.
07 - Allow to cool slightly, then garnish with fresh parsley. Serve warm.