In a large bowl, mix together the flour and salt. Add the cold butter and use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs.

Gradually add the ice water, one tablespoon at a time, mixing gently until the dough comes together. Form the dough into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.

Preheat your oven to 400°F (200°C).

In a bowl, combine the sliced apples, cheddar cheese, thyme, and honey. Toss to combine and set aside.

On a lightly floured surface, roll out the chilled dough into a 12-inch circle. Transfer to a parchment-lined baking sheet.

Spoon the apple and cheese mixture into the center of the dough, leaving a 2-inch border. Fold the edges of the dough over the filling, pleating as necessary.

Brush the crust with the beaten egg to give it a golden color during baking.

Bake in the preheated oven for 25-30 minutes or until the crust is golden brown and the apples are tender.

Allow the galette to cool for a few minutes before slicing. Serve warm or at room temperature.