INGREDIENTS
1 tbsp
sour cream
1 tbsp
fresh lemon juice
2 tbsp
ice water, (plus extra if needed)
1 1/4 cups
unbleached all-purpose flour, (plus more for rolling)
1/2 tsp
coarse sea salt, (divided)
1/3 cup
plus 1 teaspoon granulated sugar, (divided)
8 tbsp
cold unsalted butter, (cut into small pieces)
3/4 cup
fresh blackberries
3/4 cup
fresh raspberries
4 1/2 tsp
arrowroot ((or cornstarch))
1
large egg, (lightly beaten)
Sanding Sugar or Turbinado sugar for sprinkling