In a bowl, combine flour, butter, and sugar. Mix until it resembles coarse crumbs. Add cold water and form into a dough. Wrap in plastic wrap and chill for 15 minutes.

In a bowl, toss peach slices with sugar and lemon juice. Set aside.

Preheat the oven to 200°C (400°F).

Roll out the dough into a rough circle on parchment paper. Transfer the parchment with the dough onto a baking sheet.

Sprinkle almond flour evenly over the center, leaving a 2-inch border. Arrange peach slices over the almond flour.

Fold the edges of the dough over the peaches, pleating as you go.

Brush the crust with beaten egg and sprinkle sliced almonds over the top. Bake for 25-30 minutes, or until the crust is golden brown and the peaches are tender.

Let cool slightly and drizzle with honey if desired. Serve warm or at room temperature.