Sift 200g of flour and a pinch of salt in a bowl.
Add 100g butter and mix with your fingers until it looks like crumbs.
Add 2 egg yolks and 4 tbsp cold water. Combine into a pastry, use more water if needed.
Greese or line tart dish.
Roll out pastry on a lightly dusted surface to be about 1/2cm thick.
Add pastry to the dish, leave the overhang. Pop in the fridge for 20 minutes.
Preheat the oven to 170 fan.
Prick the pastry base with a fork.
Line with greaseproof paper and then top with baking beads or rice.
Pop in the oven for 10 minutes.
Remove the rice or beads and greaseproof paper and return to the oven for 5 minutes.
Trim the excess pastry off.
Melt 180g of butter.
Add 3 eggs, 3 egg yolks, 115g caster sugar, 3.5 tbsp grapefruit marmalade and the melted butter into a bowl.
Squeeze about half a lemon into the bowl.
Whisk all the ingredients and pour into the pastry case.
Bake in the oven for a further 20-35 minutes.
Serve, optionally with cream.
