Cook all the ingredients.
Mix flour and salt on a work surface. Grate cold butter (from the freezer) on a coarse grater. Chop everything with a knife until fine crumbs.
In the middle of the flour crumbs, make a deepening, add cold water, quickly knead the dough. Roll the dough into a ball, put in a bag and put in the refrigerator for at least 1 hour.
Just before you take out the dough from the refrigerator, prepare the filling. Cut strawberries in half, if large - in quarters. Mix with potato starch and 1 tbsp. Sahara. If the strawberries are not very sweet, then add 2 tbsp.
Remove the dough from the refrigerator, roll it into a layer on a parchment sheet. Put strawberries in the middle of the dough, leaving the edges 4-5 cm free. Bend the edges of the biscuit with an overlap.
Grease the edges with an egg and sprinkle with sugar. Preheat the oven to 180 degrees. Bake a biscuit 30-35 minutes until golden brown. Allow the finished baking to cool completely.