Combine the flour, icing sugar and salt. Rub in the cold butter, then mix in the egg yolk and enough cold water to form a dough.
Chill the dough for 30 minutes. Roll it out and line a 23 cm tart tin.
Chill the lined tin for 15 minutes. Line with parchment, add baking weights and bake at 180°C conventional (160°C fan) for 15 minutes.
Remove the weights and parchment, then bake for another 8 to 12 minutes. Cool completely.
Whisk the eggs and sugar together, then stir in the lemon juice and zest.
Cook over gently simmering water, stirring constantly, for around 8 to 12 minutes, until the mixture thickens enough to coat the back of a spoon.
Remove from the heat and whisk in the butter until smooth.
Pour into the cooled pastry shell and refrigerate for at least 3 hours, until set.
Arrange the dry, sliced strawberries over the chilled filling.
If desired, brush the fruit with warmed, thinned jam. Keep refrigerated until serving.