Preheat oven to 190°C. (380°F.)
Preparation time: 40 minutes, plus 1 hour chilling time
Cooking time: 55 minutes

Making the sweet pastry

1. In a large bowl, with a spatula or wooden spoon, mix the soft butter and icing sugar to a cream; then beat in 2 of the egg yolks.
2. Add the flour and, with your fingertips, rub the butter mixture and flour together to achieve a crumbly texture.
3. Add the water and press the mixture together to form a ball.
4. With the palms of your hands, knead the pastry on a lightly floured work surface until it is blended (maximum 30 seconds - do not overwork the pastry or it will be hard and lose its crumbly texture).
5. Flatten the pastry slightly with the palm of your hand, wrap in cling film and refrigerate for 30 minutes (this helps the dough lose its elasticity).

Making the lemon cream

1. In a large bowl, mix together the eggs, sugar, lemon juice and zest and whisk for a few seconds. Add the cream and whisk it in, then place in the fridge.

Rolling out the pastry

1. On a lightly floured work surface, evenly roll out the pastry into a circle 3 mm (1/8 in) thick.

Lining the tart tin

1. Roll the pastry over the rolling pin and unroll it over a 24 cm (91/2 in) loose-bottomed tart tin.
2. With one hand lift the pastry and with the other gently tuck it into the bottom edge of the tin so that it fits tightly. Be careful not to stretch it.
3. Cut off excess pastry by rolling the pin over the top edge of the tin.
4. Take a small ball of pastry and gently press it all around the base of the tart to ensure a snug fit.
5. Prick the base of the pastry all over with a fork and refrigerate for 30 minutes (this helps prevent shrinkage during cooking). Meanwhile, preheat the oven to 160°C (325°F).

Cooking the pastry

1. Line the pastry case with aluminium foil and fill with dried beans, pushing them against the side. Bake for 10 minutes, then remove from the oven and lift out both foil and beans.
2. Return the tart tin to the oven and bake for a further 20 minutes.
3. Brush the inside of the pastry with the remaining egg yolk and return to the oven for 1 minute (this creates a seal on the pastry and prevents it becoming soggy when the lemon cream is added).
4. Turn the oven down to 140°C (275°F).

Cooking the lemon tart

1. Pour the lemon cream mixture into a saucepan and warm it gently (this is to speed up the cooking time of the tart), being careful not to heat it too much or it will scramble.
2. Pour the warm mixture into the pastry case and bake for 25 minutes, until barely set.
3. Remove from the oven and leave to cool for at least 1 hour, then dredge icing sugar around the edge of the tart.
4. Remove the tart from the tin and place on a serving plate.