River Walk Strawberry Pie A San Antonio, Texas recipe. 1 (9-inch) graham cracker crust 10 ounces frozen strawberries 1 cup granulated sugar 2 egg whites 1 tablespoon fresh lemon juice Dash of salt 1/2 cup whipping cream, whipped 1 teaspoon vanilla or almond extract Thaw strawberries in a colander. When they reach room temperature, combine them in a large mixing bowl with the sugar, egg whites, lemon juice and dash of salt. Beat until very stiff, about 15 to 20 minutes. Fold the whipped cream and vanilla or almond extract into the beaten berry mixture and pour into the prepared pie crust. Freeze the dessert for 2 to 3 hours or until very firm.