Add 200 ml whole milk and 3 teabags roasted green tea to a saucepan. Leave them to steep while you prepare your other ingredients.
Whisk 2 pasteurized egg yolk, 75 g sugar and 1 tsp cornstarch together in a heatproof bowl.
Heat up the pan of milk and stir the tea around to help release the flavor. Don't let it to boil.
When you start to see tiny bubbles appear around the edges of the pan, add 200 ml heavy cream.
Continue to heat on medium-low until the little bubbles start appearing around the edge again. Once they do, turn off the heat and remove the teabags. Use tongs to squeeze the teabags.
Temper the eggs and sugar mixture by adding a ladle of the hot milk/cream to the bowl and whisk it well. This prevents the egg chunks in the mixture.
Gradually pour the rest of the milk and cream into the bowl while whisking.
Once well incorporated, pour the mixture back into the sauce pan. Pour it through a sieve to catch any lumps.
Stir continuously on a low heat until it thickens into a custard consistency.
Transfer it to a loaf tin/metal container and cover the top with plastic wrap touching the surface. (This is to prevent a skin from forming.)
Allow the mixture to cool down, speed up the process by placing the container in a casserole dish with ice.
Once it's cool, put it in the freezer and whisk every 30 minutes for 3 hours. (6 times in total)
After the final churn, freeze for 3-4 hours.
Enjoy! (After 4 hours or so, it will need 5-10 minutes on the counter top to soften before serving.)