Prepare crust according to package directions.
Since you only need one crust for the recipe, if your recipe makes more than one, wrap one half of the dough in plastic wrap and store in a sealed plastic bag in the freezer. Or be like me and double the rest of this recipe to make two galettes right now!
Flatten the dough you will be using, wrap in plastic wrap and store in the fridge for at least an hour.
When your dough is almost done chilling, preheat oven to 350°F.
Add all filling ingredients in a medium mixing bowl and toss to combine.
On a large sheet of parchment paper or silicon baking mat, roll out your pie dough into a roughly 12" circle.
Add filling into the center, leaving a couple inches of space around the edges.
Carefully fold the edges of the crust up and around filling, working in small folds in one direction and lightly pinching each fold together to ensure they stay in place.
Brush the crust with lightly beaten egg yolk.
Carefully transfer your parchment paper/silicon mat with the galette to a baking sheet and bake for 40-45 minutes, or until crust is crispy and golden brown.
Let cool on baking sheet.