In a mixing bowl, combine flour, sugar, and salt. Add in cold butter and vegetable shortening. Using a pastry cutter or your hands, incorporate the fat into the flour until the mixture resembles coarse sand.

Gradually add in ice water, one tablespoon at a time, and mix until the dough comes together into a ball.

Flatten the dough into a disc and wrap in plastic wrap. Refrigerate for at least 30 minutes.

Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.

On a floured surface, roll out the dough into a circle, about 1/8 inch thick.

In a separate bowl, mix together apples, sugar, lemon juice, and cinnamon. Arrange the apple slices in the center of the dough, leaving a 2-inch border around the edge.

Fold the edges of the dough over the filling, pleating as you go. Brush the dough with beaten egg.

Bake for 35-40 minutes, until the crust is golden brown and the apples are tender.

In a small saucepan, heat apricot preserves over low heat until melted. Brush the melted preserves over the apples.

Serve the galette warm or at room temperature.