Kosher salt and freshly cracked black pepperto taste
1teaspoonFresh thyme leaves
4ouncesGruyere cheeseshredded
4ouncesFontina cheeseshredded
4-6slicesProsciutto
Freshly grated nutmeg
Instructions
Instructions
Preheat your oven to 400 degrees Fahrenheit or 200 Celsius.
Heat 2 tablespoons butter and 2 tablespoons olive oil in a large skillet over medium heat.
Add sliced onions to skillet. Season with salt and pepper and cook, stirring frequently, for about 25 minutes until deep caramel color.
Remove from heat and stir in thyme leaves and a pinch of nutmeg.
Roll out thawed puff pastry on a floured surface to fit baking sheet. Transfer to sheet, drizzle remaining tablespoon of olive oil, and season with salt and pepper.
Spread caramelized onions evenly over puff pastry.
Sprinkle shredded gruyere and fontina cheeses over the onions.
Gently lay prosciutto slices on top. Bake 20 to 25 minutes until golden brown and bubbly.
Let it cool slightly before slicing.
Notes
Serve hot for best flavor and texture. Can store leftovers in fridge.