Rustic Apple Tart (Martha Stewart)

Ingredients:
1 sheet of frozen puff pastry, thawed
Flour, for work surface
3 Granny Smith Apples
1/3 cup sugar
1 large egg yolk, beaten with 1 teaspoon of water, for egg wash
2 Tablespoons unsalted butter
2 Tablespoons apple jelly, or apricot jam

Directions:
Preheat oven to 375 degrees. Open pastry sheet and remove paper Fold sheet back up. On a lightly floured work surface, roll out pastry c=sheet (still folded) to an 8-by-14-inch rectangle. Trim edges with a pizza cutter or sharp paring knife. Transfer to a baking sheet; place in freezer. Peel, core, and slice apples 1/4 inch thick.

Brush pastry with egg wash, avoiding edges. Use a sharp paring knife to score a 3/4 -inch border around pastry (do not cut all the way through). Place apples inside border, and dot with butter. Bake until pastry is golden and apples are tender, 30 to 35 minutes.

In the microwave or a small saucepan, heat jelly with 1 tablespoon water until melted. Brush apples with glaze. Server tart warm or at room temperature, cutting into pieces with a serrated knife.