Preheat the oven to 350 °Grease a 9x13 inch baking dish.
Line a rimmed baking sheet with aluminum foil.
In a medium bowl, stir the flour, brown sugar, pecans and melted butter. Toast in the oven until walnuts are fragrant, about 10-13 minutes; stir occasionally. let cool.
Spread the pecan mixture evenly over the bottom of the 9x13 inch dish and pat it down into the pan with your hands.
Strawberry Filling
Combine the sliced strawberries in a medium bowl with 1/2 cup sugar and mash with a fork or potato masher, mix until the sugar is dissolved. Set aside.
In a large deep bowl, whip the egg whites with the lemon juice until they start to form peaks. Gradually add 1/4 cup white sugar while continuing to whip to firm peaks - About another 7-8 minutes. Fold in the strawberries.
In a separate bowl, whip the cream with an electric mixer just until soft peaks form.
Fold the whipped cream into the strawberry mixture.
Spoon the mixture over the prepared pecan crust in the dish and spread evenly.
Cover and freeze for 6 hours, or overnight.
Cut into squares to serve and add a dollop of whipped cream and a whole strawberry for garnish.
Notes
Use pasteurized egg whites, the equivalent will be on the carton.