To make the pastry:
Pre heat the oven to 180C
Using the dough blade of the food processor add the flour, sesame seeds and salt. With the motor running add the maple syrup and oil until combined. Reduce the speed of the processor and slowly add the cold water until the mixture forms a ball. Place in a plastic bag and set aside in the fridge for 15 minutes.
Lightly oil and flour a 24 cm pie dish. Roll the pastry out to approx 4mm thick. Line the dish with the pastry. Using a fork pierce around the pastry before placing it in the oven to cook for 15 minutes.
To make the filling:
Peel the custard apple and remove the seeds. In a food processor combine the custard apple, ricotta, lime juice and rind. Dissolve the gelatin completely in boiling water and stir it through the filling. Fill the pastry case and refrigerate until it has completely set.
Note: Gelatin is created by prolonged boiling of animal skin, connective tissue or bones. Vegetarians who eat dairy but prefer not to use gelatin can use agar instead.