2 tablespoons unsalted butter
1 medium red onion, thinly sliced
4 Fuji apples, peeled, cored, and sliced
⅓ cup firmly packed light brown sugar
¼ cup brandy
3 tablespoons lemon juice
3 tablespoons fresh sage leaves, torn into small pieces
1 teaspoon kosher salt
1 cup grated Gruyère cheese
½ (17.3-ounce) package frozen puff pastry, thawed
1 tablespoon water
1 large egg white, lightly beaten
1. Preheat oven to 400˚. Line a rimmed baking sheet with parchment paper; set aside.
2. In a medium saucepan over medium heat, melt the butter. Add the onion, and cook until tender, about 15 minutes; transfer onion to large bowl, and set aside.
3. In a large bowl, combine the sliced apple, brown sugar, brandy, lemon juice, sage, and salt; toss to combine. Place the mixture in the medium saucepan over medium heat; cook until apples are tender, about 15 minutes. Add apples and the Gruyère to the bowl with the onion.
4. On a floured surface, roll the puff pastry dough into a 12×10-inch rectangle. Starting 2 inches from one long side and 2 inches from each short side, fold short edges over filling. Beginning at the edge close to filling, roll up strudel jelly-roll style. Place strudel, seam side down, on prepared baking sheet.
5. In a small bowl, whisk to combine water and egg white. Using a pastry brush, lightly coat top of strudel. Bake for 25 to 30 minutes, or until golden brown. Allow strudel to rest for
10 minutes before slicing and serving.
This Savory Harvest Strudel is a lovely dish that makes a pretty presentation.