Preheat the oven to 190'C.
Split the vanilla pod into half and scrape out the seeds. Place into a bowl with the egg yolks and sugar, then whisk until pale and fluffy. Whisk the corn starch into the egg mix a little at a time.
Pour the cream and the milk into a saucepan and bring to the boil. Pour slowly over the egg mix. Stir in the matcha tea. Return the mix to the heat and cook until it has thickened. Set aside and allow to cool, whisking as it cools.
Soften the butter and brush the inside of the ramekins in an upwards motion. Dust with caster sugar and place in the fridge.
Whisk the egg whites until foaming and then add the sugar. Continue whisking until you have stiff peaks.
Place 30 grams (a tablespoon) of the matcha tea cream into a mixing bowl and whisk in 1/3 of the meringue until smooth. Fold in the remaining egg whites. Fill the ramekins with the souffle mix, smooth the top with a palette knife and then wipe away a 2 mm band of the mix from the edges of the ramekin. Bake for 10-12 minutes depending on the size of the ramekin.
Serve immediately with a dusting of icing sugar.
«For a perfect souffle using a pastry cream base, the pastry cream should be 10-15% of the weight of the meringue.»