Creating a Rustic Honeycrisp Apple Galette is straightforward. Follow these simple steps:

1. Make the Dough: In a large bowl, whisk together the flour, salt, and granulated sugar. Add the cold, cubed butter and mix until the mixture resembles coarse crumbs.
2. Add Ice Water: Gradually add ice water, one tablespoon at a time, mixing until the dough comes together. Be careful not to overmix.
3. Chill the Dough: Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.
4. Prepare the Filling: In a bowl, toss the sliced Honeycrisp apples with brown sugar, cinnamon, and lemon juice. Set aside to allow the flavors to meld.
5. Preheat the Oven: Preheat your oven to 400°F (200°C) while you roll out the dough.
6. Roll Out the Dough: On a floured surface, roll the chilled dough into a 12-inch round. Transfer it to a parchment-lined baking sheet.
7. Add the Filling: Arrange the apple mixture in the center of the dough, leaving a 2-inch border around the edges.
8. Fold the Edges: Gently fold the edges of the dough over the apples, creating a rustic crust. The center will remain exposed.
9. Brush with Egg Wash: Brush the folded edges with the beaten egg and sprinkle with coarse sugar for a beautiful finish.
10. Bake: Bake in the preheated oven for 30-35 minutes, or until the crust is golden brown and the apples are tender.
11. Cool: Remove from the oven and allow to cool for 10-15 minutes on the baking sheet before slicing.

These steps will guide you in creating this incredible Rustic Honeycrisp Apple Galette effortlessly.