For the pastry:
175g plain flour
100g cold butter, cut in small pieces
1 tbsp icing sugar
1 egg yolk
For the filling:
2 level tbsp cornflour
100g golden caster sugar
2 large lemons, zested
125ml fresh lemon juice (from 2-3 lemons)
1 small orange, juiced
85g butter, cut into pieces
3 egg yolks and 1 whole egg
For the meringue:
4 egg whites, room temperature
200g golden caster sugar
2 tsp cornflour
Step 1: To prepare the pastry, put the plain flour, butter, icing sugar, egg yolk and 1 tbsp cold water into a food processor. Stop the food processor when the mix blends well, not too well.
Step 2: Put the pastry on a floured surface, mix together until it is smooth, then roll out and line. Trim edges in a way that they are neat. Press the pastry into the flutes. Prick the base with a fork, line with foil, and leave it for 30 mins-1 hr.
Step 3: Place a baking sheet in the oven and heat the oven to 200C/180C fan/gas 6. Bake the pastry case filled with dry beans for 15 minutes, then remove the foil and bake for another 5-8 minutes until the pastry is cooked. Leave it aside.
Step 4: While baking the pastry, prepare the filling. Mix the cornflour, golden caster sugar and lemon zest in a saucepan. Gradually stir in the lemon juice and make the orange juice up to 200ml with water and strain it into the pan. Cook this on a medium heat, stir constantly until it is smooth and thick.
Step 5: After this, the mixture bubbles, once the mixture bubbles, remove from the heat and beat the butter until melted. Also beat the egg yolk and the whole egg together, stir into the pan and return to a medium heat. Keep stirring constantly for a few minutes, until it thickens and bubbles up. Take off the heat and leave it aside.
Step 6: In a bowl, put the egg whites, whisk until it turns to soft peaks, and then add 100g of the golden caster sugar, whisk them at intervals adding a spoonful of sugar at a time without overbeating. Whisk in the cornflour, then add the remaining 100g of sugar until it is smooth and thick.
Step 7: Reheat the filling quickly and pour into the pastry case. Put spoonfuls of meringue around the edge of the filling immediately, then spread in a way that it touches just the pastry. Pile the rest into the centre, spread so that it touches the surface of the hot filling to cook, then give it all a roll.
Step 8: Return the meringue to the oven for about 18-20 minutes until it is crisp and a little bit coloured. Leave the pie to sit in the tin for 30 minutes, then remove and leave for at least another 30 mins-1 hour to cool before slicing. Eat the same day.