Take a bowl, add the flour, sugar and salt to whisk together. Then add in the cubed butter and rub it with the flour mixture.
Make a well in this flour mixture and pour in the cold buttermilk. Bring the dough together with the help of a fork.
Now place this dough on a floured surface, divide the dough in two parts and knead it well. Wrap each dough part in separate plastic wraps and refrigerate for 1 hour.
Next, take a bowl, add in the strawberries, sugars, cornstarch, salt, lemon juice together. Toss these ingredients well together and keep it aside for 10 minutes.
Place one dough part on a floured surface, roll the crust for the bottom part about 1/8″ thick and about 12″ in diameter. Place this on a pie pan and trim the edges of the pan.
Now carefully pour the strawberry filling on top of this crust.
Next, take the other dough part and roll it in the same manner. With the help of a knife, slice this dough into 1-inch wide strips and weave the crust strips on top of the pie.
Preheat oven to 204 degrees C. Line a baking sheet with parchment paper and set aside.
Brush egg wash over the pie crust and sprinkle sugar on top.
Place the pie on the baking sheet and bake for 15 minutes, then reduce the temperature to 148°C and continue baking for another 30 minutes .
Once cooked, allow it to cool completely and cut slices to serve.