1 large egg
2 cups all-purpose flour
1 tsp kosher salt
½ pound chilled unsalted butter, cut into small pieces
2 lbs Granny Smith apples, sliced crosswise into 1/4"-thick slices, seeds removed
1 tbsp honey
1 tbsp lemon juice
¼ cup granulated sugar
1 tsp ground cinnamon
1 tbsp heavy cream
Brown sugar for sprinkling the edge
1. Crack a cold egg into a liquid measuring cup, and beat it with a fork. Add enough cold water to make ½ cup. Meanwhile, in a large bowl, combine all-purpose flour, and 1 teaspoon salt.
2. Using your fingers, run ½ pound butter into the flour mixture until there are no pieces of butter larger than a pea.
3. Add cold egg mixture to the flour, and stir until a ball of dough forms. Wrap dough in plastic wrap, then place it in fridge to chill for at least 1 hour.
Note: chilling the dough allows the gluten that has developed to relax, which will make rolling the dough much easier.
4. Preheat the oven to 375ºF Take dough out of refrigerator and let it sit. Use a mandoline or slice apples very thin.
5. In a large bowl, whisk together honey, lemon juice, granulated sugar and cinnamon. Add apples and gently toss to coat the apples. On a floured surface, roll dough out to a ¼ inch thick and transfer to a parchment-lined baking sheet.
6. Arrange layers of apple slices in the center, leaving a 2-inch border. Fold in the edges. Brush edges with heavy cream then sprinkle with brown sugar. Bake tart for about 45 minutes.