Adapted from SMH’s Good Living.
My only significant change to the recipe has been to change the pastry from a sweet shortcrust to a plain, and slightly salty, shortcrust pastry; it offers a better balance of flavour.

Pastry
1.5 cups flour
1/4 tsp salt
100g (3oz) butter
2-3 tblsp chilled water

Filling
2 egg yolks
100g (3oz) caster sugar
1.5 tbsp cornflour
1 cup (250g) sour cream
1 tsp vanilla extract or vanilla bean paste
150g (1 cup) macadamia nuts, toasted

To make the pastry, stir the flour and salt together in a large bowl. Remove the butter from the fridge and grate using a box grater. Add the butter to the flour, toss to coat, gently rub the butter into the flour until it resembles coarse bread crumbs. Add just enough water for the dough to come together. Form the pastry into a flat round. Wrap in cling film and place it in the fridge for at least 30 minutes.

Preheat the oven to 180C (350F). Grease one 20cm (8 inch) loose bottom flan tin with butter. Remove the pastry from the fridge and roll it into a round large enough to line the tin (I find it is easier to roll the pastry out between two sheets of baking paper). Line the tin with the pastry, trim, pierce the bottom many times with a fork. Line the pastry with a piece of baking paper and fill with baking weights. Bake for about 20 minutes before removing the baking weights and paper. Bake for a further 5 minutes or so until the pastry is golden brown all over. Allow to cool before filling.

To make the filling, heat the sour cream in a saucepan. In a bowl mix together the egg yolks, caster sugar and cornflour. When the sour cream is hot slowly add it to the egg mix, while constantly stirring, until all combined. Place the custard into the saucepan and heat, without boiling, until it has thickened. Remove from the heat and add the vanilla. Allow the custard to cool.

To assemble, place half the macadamia nuts in the pastry case, fill with custard and top with the remaining macadamia nuts.