Preheat the oven to 180 degrees Celsius (350 degrees Fahrenheit).
Combine all ingredients in a large bowl until it forms a firm dough - add the water a few tablespoons at a time so that you don’t add too much!
You can keep this pastry dough in the fridge for up to a day if you like, but there is no need to chill it before using.
Place the pastry dough into a greased pie dish and use your fingers to carefully press it across the bottom and up the sides of the dish - I used a 20.5 cm/8 inch pie dish.
Use a fork to pierce the surface (remember the sides too!) of the pastry, so that it doesn’t puff up in the oven. Alternatively, you can use baking beans.
Bake in the oven for around 30 minutes, until the pastry crust is firm to the touch and golden brown.
Leave to cool slightly before pouring in the strawberry jelly.
For the strawberry jelly:
Place the strawberries, lemon juice and maple syrup in a food processor or blender (or use a hand-held stick blender) and whizz until completely smooth.
Transfer the mixture into a measuring jug and top up with water until the mixture reaches the 300ml (1 ¼ cup) mark.
Transfer the mixture into a pan and bring to the boil.
Turn down the heat, add the agar, mix well and simmer for a few minutes before turning off the heat.
The strawberry jelly needs to be poured into the pastry crust immediately otherwise it might set in the pan!
To assemble:
Place the sliced strawberries into the pastry crust.
Pour over the jelly mixture.
Leave to cool and place in the fridge for at least a few hours until the jelly has set completely.
Serve with coconut whipped cream, if desired.
Tastes best when fresh, but keeps covered in the fridge for up to a few days.