For the pastry:
- Whisk together the flours, baking soda and salt. Slice or scrape the oil with a spoon into chunks no bigger than a tablespoon and drop them into the flour mixture, covering them with flour as you go.
- Use a pastry cutter or two butter knives cutting against one another to chop the coconut oil into the flour until a rough meal is formed. It is okay if there are still some chunks.
- Gradually add the cold water, using the pastry cutter or knives to mix it all together. Form the dough into a ball and pat into a large rectangle.
- Gently roll the dough into a longer rectangle and fold like a business letter (into thirds). You can dust with more flour as you are doing this. Fold again from the short side. Wrap in cling wrap and refrigerate for 20 minutes.
- Halve the dough and knead gently if bits of coconut oil has hardened. Roll the dough to about 4mm thick into a rectangle the size of the tin or slice tray you are using for the slice. I used a 2.6L glass Pyrex dish. Ensure the dish/tin is lined with baking paper that overhangs the sides. The dough is quite delicate so make sure you gently transfer it to the base of the dish.
- Place the second half of the dough onto a lined baking tray and roll into a rectangle of the same size. It is easier to roll it while it’s on the tray as this avoids it breaking as you transfer it.
- Bake the pastry for 10-15 minutes or until beginning to turn golden. Remove from the oven and allow to cool on the tray and in the dish/tin. Do not try to move the pastry as it will crack.
For the custard:
- Place ½ cup of the soymilk in a small bowl and pour over the agar agar powder in a thin layer. Set aside for 10 minutes and allow the agar agar to dissolve.
- Place the soymilk in a saucepan over medium heat and warm gently for about 10 minutes.
- Add the arrowroot powder, honey, vanilla and dissolved agar agar and whisk until smooth. Add the coconut cream and return to the heat, stirring constantly until the mixture thickens and boils. Add the coconut oil, stirring until well combined.
- Remove the saucepan from the heat and whisk in the egg yolks one at a time until smooth.
- Pour into pastry-lined pan and set aside to cool slightly before placing the other piece of pastry on top. Refrigerate overnight.
For the icing:
- Halve the passionfruit and scoop the pulp into a small mixing bowl. Add the tahini, honey and coconut oil and stir until smooth and well combined.
- Pour over the top layer of pastry and spread evenly. Return the slice to the fridge for at least 10 minutes for the icing to set.
- Remove the slice from the dish/tin and use a sharp knife to cut it into pieces. Store in the refrigerator and enjoy!