Place strawberries in a blender and puree until smooth. Pour the pureed strawberries through a mesh strainer. Add the lemon juice. Transfer to a saucepan over medium-high heat and bring to a boil.

Reduce the heat and add the sugar and salt. Simmer for 15 minutes. Whisk the water and cornstarch in a small bowl. Add the cornstarch slurry to the saucepan and whisk until it has slightly thickened. Allow to cool and then place in the refrigerator overnight before serving.

Combine flour, sugar, baking powder, and salt in a medium bowl. Add the cubed butter and combine with your hands until it resembles coarse cornmeal. Mix in the strawberries. Place in the refrigerator and let rest for 15 minutes.

Remove from the refrigerator, add the buttermilk and heavy cream, and stir until the dough barely comes together. Transfer to a floured countertop and work until the dough just comes together. Roll the dough into a 1-inch tall rectangle. Fold the top third of the dough towards you.

Next, fold the bottom third over the first fold. Reroll the dough again and repeat the fold. Reroll the dough once more. Cut the dough into 9 squares. Place the pieces on a baking sheet with parchment paper. Place in the freezer for 20 minutes.

Preheat oven to 425°F. Remove and brush each of the biscuits with melted butter and sprinkle coarse sugar and flaky salt on top. Bake for 15 to 20 minutes, or until golden brown. Transfer to a wire rack and allow to cool.

Place the ingredients for the whipped cream in a bowl and whisk until it reaches stiff peaks. Place in the refrigerator to keep cool until you are ready to use it.

Top a biscuit with whipped cream and strawberry sauce. Place the strawberries on top and serve.