Bake the pie crust in the oven. You can use homemade or a store bought pie crust. If you're using homemade, bake as usual. If you are using store bought, follow the instructions on the package to bake it.
Add 3/4 of the strawberries (whole, stems removed) into the baked pie crust. I like to set them in pointed side up.
Add the remaining 1/4 of the strawberries into a medium-sized saucepan. Add sugar and mash berries until they're mushy. Place on the stove on medium heat and bring to a boil, stirring frequently so the sugar does not burn.
In a small bowl mix together cornstarch and water with a fork.
Add cornstarch mixture to strawberries in the saucepan, a little at a time. Bring to a boil and then reduce heat to simmer, mixing frequently until it thickens up, about 10-15 minutes.
Pour hot mixture over the berries in the pie crust.
Cover the pie with plastic wrap and place in the refrigerator for at least 2 hours to chill. You can also chill overnight (my preference). Cut pie into slices, adding a little whipped cream on top of each slice when serving (optional but delicious!).