Idaho Potato and Caramelized Onion Tart with Swiss Cheese
A savory tart featuring thinly sliced Idaho potatoes as the base, topped with deeply caramelized onions sweetened with sugar, melted Swiss cheese, and a golden buttery breadcrumb topping. The potato slices form a rustic crust that becomes tender and golden during baking, while the onions develop rich, sweet flavors through slow cooking. Perfect for brunch gatherings, light dinners, or as an elegant side dish for holiday meals. The combination of earthy potatoes, sweet caramelized onions, and nutty Swiss cheese creates a comforting yet sophisticated dish.
Ingredients
- 1 large Idaho potato, peeled and thinly sliced
- 6 tablespoons butter, melted, divided
- 1 teaspoon seasoned saltkosher salt1:1low-sodium
reduce sodium content
- 2 large onions, thinly sliced
- 1 teaspoon sugar
- 1 cup Swiss cheese, shredded
- ½ cup dry breadcrumbs, plain or seasoned
Instructions
- 1
Preheat oven to 375 degrees
- 2
Toss potato slices with 1 tablespoon melted butter and seasoned salt
- 3
Arrange potato slices in tart pan with removable bottom or pie pan
- 4
Bake potatoes for 20 minutes
- 5
Saute onions in 3 tablespoons melted butter over medium heat until soft and beginning to brown
- 6
Turn heat to low, sprinkle onions with sugar and continue cooking until deep brown
- 7
Remove potatoes from oven and spread onion mixture over them
- 8
Sprinkle cheese over onions
- 9
Combine breadcrumbs with remaining 2 tablespoons melted butter
- 10
Sprinkle breadcrumb mixture over cheese
- 11
Bake additional 10-15 minutes until cheese melts and topping is golden brown
- 12
Cool 5 minutes before serving
Tips
Use a mandoline slicer for uniformly thin potato slices to ensure even cooking and professional presentation.
Cook onions slowly over low heat after adding sugar to prevent burning while achieving deep caramelization.
Let the tart rest 5 minutes before serving to allow the cheese to set slightly for cleaner slicing.
Good to Know
Refrigerate covered for up to 3 days. Reheat in 350F oven for 10-15 minutes.
Can assemble completely and refrigerate up to 1 day before final baking. Add 5-10 minutes to baking time if cold.
Serve warm or at room temperature. Cut into wedges for individual portions.
Common Mistakes
Slice potatoes uniformly to avoid uneven cooking
Keep heat low when caramelizing onions to avoid burning
Don't skip the cooling time to prevent cheese from being too runny when serving
Substitutions
Dairy-Free Swaps
General Alternatives
FAQ
Can I use other types of potatoes instead of Idaho potatoes?
Yes, but Idaho potatoes work best due to their starchy texture that creates a good base. Yukon Gold can substitute but may be less sturdy.
What if I don't have a tart pan with removable bottom?
A regular 10-inch pie pan works perfectly fine. The removable bottom just makes serving easier but isn't essential for the recipe.
How long will this keep in the refrigerator?
The tart will keep covered in the refrigerator for up to 3 days. Reheat in a 350F oven for best texture and flavor restoration.