Start by making the pastry. Place the plain flour, icing sugar and salt in a large bowl and whisk to mix or place in a food processor and pulse until combined.
Add the cold diced vegan block butter and rub it in using your fingers or blend with the food processor until the mixture resembles fine breadcrumbs and no lumps of fat remain.
Add the tablespoon of cold vodka (or water) and mix; drizzle in a little cold water as needed to bring the pastry together into a ball.
Cover the pastry and pop it in the fridge for half an hour until it has firmed up a bit.
Once the pastry has chilled, roll it out thinly on a floured surface until it is large enough to line a 25cm/10 inch round tart tin.
Gently transfer the pastry to the dish and press it right into the corners. Trim off the excess pastry and prick the base all over with a fork.
Place the pastry base in the freezer for twenty minutes while you preheat the oven to 200°C/180° fan/400°F/gas mark 6.
When the pastry is nice and cold, line it with tin foil, making sure that you press it right into the corners, then fill it with baking beans or dried rice. Make sure you spread them right into the corners.
Bake for 20 minutes then remove the tin foil and rice/beans and return the tart shell to the oven for 10-15 minutes, until it is pale golden and crisp. Turn the oven down to 180°C/160° fan/350°F/gas mark 4.
While the pastry is baking prepare the filling. Place the lemon juice, silken tofu, coconut cream, cornflour, sugar, melted butter and a pinch of ground turmeric in a blender and blitz until completely smooth, scraping down the sides as necessary. Stir in the lemon zest.
When the pastry case has finished baking, carefully pour in the filling and place it back in the oven.
Bake for 30-40 minutes until the filling is set but still has a wobble. Remove from the oven and allow it to cool completely before refrigerating. Once cool, chill the tart for at least 4 hours before serving.