Add the frozen strawberries and lemon juice into a medium saucepan.
In a medium bowl, combine the sugar and cornstarch. Whisk together, then pour over the frozen strawberries.
Let the strawberries cook covered on medium-low heat for 15 minutes until the strawberries are starting to get soft. Then, turn your heat up and let the strawberries get to boiling. Boil for 5 minutes stirring constantly. Then remove from heat. Mash the strawberry with a fork. Set them aside to cool.
While your strawberries are cooling down, pre-heat your oven to 350o F.
Pour the slightly cooled strawberry filling into your crust. Place the other pie crust on top of strawberry and cut the excess dough. Cut little dent with a fork in the top pie crust to let the steam exit the inside of the pie.
Bake for 35-40 minutes or until the top is starting to look golden brown.