Combine 2 1/2 cups flour, the butter and salt in a food processor. Pulse until mixture is the size of peas. With processor running, slowly pour in 1/4 to 1/2 cup ice water, until dough just comes together. Form into 2 equal rounds, wrap in plastic wrap and refrigerate 2 hours.Advertisement
Heat oven to 375°. On a lightly floured surface, roll one round of dough to fit inside a 9-inch pie dish. Repeat with second round but slice into 10 strips. Place both on baking sheets and refrigerate 15 minutes.
Combine strawberries, 1/4 cup sugar, 3 tbsp flour and the lemon juice. Remove dough from refrigerator and fit whole round into pie dish. Pour in strawberry mixture. Create a lattice pattern with strips of dough. Crimp edges. Brush top and edges with egg, then sprinkle on 1 tbsp sugar.
Bake 30 minutes. Carefully wrap foil around edges of crust to prevent burning, then bake another 30 minutes, until golden. Cool completely before slicing.