To prepare the strawberry sauce:
Combine the orange juice, sugar and strawberries in a saucepan and bring to a boil. When the sugar has melted and the strawberries are softened (about 5 minutes), strain the juice through a fine mesh sieve and set aside. Remember to catch the seeds.
Pour the strawberry juice mixture back into the same saucepan. Then, using a separate pot, combine 2 tablespoons of cornstarch and 1/4 cup of strained strawberry juice and mix until there are no lumps. Add this to the rest of the strawberry juice mixture and turn up the heat. Using a wooden spoon, stir until it begins to boil again and has thickened (about 1 to 2 minutes).
Pour into a Pyrex glass, and cool for about 30 minutes. Then, cover with plastic wrap and place the sauce in the refrigerator. You can make this recipe two days ahead of time and keep refrigerated. The sauce should be served cold. To serve sauce with cake and sorbet:
Add lemon zest to the sauce. In a bowl or rimmed plate, pour 1/3 cup of strawberry sauce. Add a scoop of sorbet and a slice of cake, and sprinkle a handful of strawberries on the plate. Garnish with a fresh sprig of chopped mint or leave the leaves whole. Serve immediately.Watch Cristina make this recipe!