Cheese Tart with Leeks and Chard

For the pastry: mix together the potato starch, cornflour, brown rice flour and sweet rice flour in a mixing bowl and whisk to combine.

Add the xanthan gum, guar gum and salt and stir well.

Add the frozen butter and using an electric whisk mix on the lowest speed, until the edges of the butter pieces have started to soften.

Pour in the water and mix until absorbed.

Turn out the mixture onto a large sheet of non-stick baking paper and knead it together with your hands, just enough to bring it together.

Place another sheet of baking paper on top and gently roll the dough out to a rough rectangle, taking care not to roll over the edges.

Fold the bottom third of the dough towards the middle, then fold the top third on top of it.

Rotate the dough one-quarter turn to your right (clockwise).

Roll out the dough gently as before, until smoother and more cohesive. Fold the bottom third up and overlap the top third over it.

Rotate the dough one-quarter turn to your right (clockwise).

Repeat the turning, rolling and folding process twice more.

Wrap the folded dough in cling film and chill for 2 hours.

Remove from the refrigerator and stand at room temperature for about 20 minutes.

Repeat the turning, rolling and folding process twice more. Wrap the dough in cling film and chill for a further 2 hours, then stand at room temperature for about 20 minutes before using.

Heat the oven to 375°F. Line a large baking tray with non-stick baking paper.

For the filling: heat the oil in a large frying pan and cook the garlic for a few minutes until softened. Add the Swiss chard, leeks and water and cook until the water has evaporated. Remove from the heat and put into a large bowl and set aside to cool.

Mix together the ricotta, 1 cup Parmesan, eggs, and the Swiss chard mixture. Mix to thoroughly combine. Season to taste with salt, pepper, and nutmeg. Set aside.

Roll the dough into a large round about 1/4" thick. Place on the baking tray.

Put the filling in a large circle in the center of the round, leaving a 3" border of dough. Fold the dough up around the filling, as in the photo. Brush the top of the dough with beaten egg. Sprinkle the remaining parmesan over the filling.