Add the cornflour to a stainless steel pan. Gradually whisk in the water to make a smooth paste then whisk in the lemon juice and sugar.

Place over medium-low heat and stir until the sugar has dissolved. Cook until thickened, stirring continuously.

Turn the heat to low and add the milk, butter and turmeric, stirring until melted and smooth. Remove from the heat.

Pour the hot lemon curd into a 500ml jar. Seal and place in the fridge overnight to set before serving.