Bright, zesty and delicious, this lemon tart is such a lovely thing to serve in the warmer months. I love the intense citrus flavours that come from the pastry flecked with zest and the rich, unctuous filling.
You will need a deep 8 inch tart tin with removable base for this recipe.
Place the flour, xantham gum, margarine and vegetable fat in a food processor and pulse until the mixture is of a breadcrumb like consistency. Add the lemon zest and caster sugar and pulse for another minute. Tip in the lemon juice and 1 tbsp of cold water, pulsing as you go, until the mixture begins to pull together to form a dough. You can then add the extra water if you think it needs it. Turn the pastry in to a large bowl and, using the tips of your fingers, pull together into a ball. Knead lightly for 2 minutes until smooth and elastic to your touch. Lay the pastry between two large layers of clingfilm and roll it out – ensuring that the pastry becomes no thinner than 3mm. Peel off the uppermost layer of clingfilm and turn the pastry in to its tin, filling in any cracks or gaps that may appear with extra pastry, patted flat with your fingertips.
Preheat the oven to 200c. Blind bake the lemon pastry for 30 minutes, after 15 minutes remove the parchment and baking beans from the pastry and return to the oven for the remaining cooking time. Once the pastry is cooked and lightly golden, remove from the oven and set aside to cool down.
Place the agar flakes in a high sided saucepan with 330ml of water. Bring to the boil and leave to boil gently for 10 minutes, whisking every now and then until the agar has dissolved. Don’t worry if the liquid foams up, this is normal and why you need to use a high sided pan. Add the sugar to the liquid and continue to boil gently, whisking occasionally, for 3 – 4 minutes or until the sugar has dissolved into the liquid, then remove from the heat.
In a separate bowl, combine the lemon juice, zest and cornflour and stir together until smooth. Add this mixture and the oat cream to the agar liquid and whisk together constantly, over a medium heat, for around 5 minutes or until the mixture thickens and becomes syrupy. Take off the heat and set aside to cool for a few minutes. Pour the lemon filling into the pastry tart, leave to cool at room temperature for 30 minutes and then place in the fridge to set for 1 hour.