Preheat oven to 350 and place the rack in the oven in the lower 1/3 of the oven.
On a baking sheet, place a piece of parchment paper and sprinkle with some flour. Roll the dough out to an 8 or 9 inch circle. The dough should be no thicker than 1/4 of an inch.
In a bowl mix the strawberries, blueberries, salt, 3 tablespoons sugar and flour. Place in the center of the pie crust, leaving 2 to 3 inches uncovered. Fold the remaining pie crust on top of the berries to form the galette.
Place in the oven for 30 to 40 minutes. Until the dough is golden brown and the fruit is bubbly. Sprinkle the remaining sugar on the crust and serve warm with vanilla ice cream.