Over medium-low heat, add the heavy cream, whole milk, sugar, green tea bags, and salt to a medium saucepan. Bring the mixture to a simmer, until small bubbles appear on the edge of the saucepan. Remove from the heat and leave to steep for 30 minutes. Ring gently the tea bags to get all the flavor out and discard. Bring back to a simmer.
In a bowl, beat the egg yolks. Slowly whisk in a quarter of the hot mixture into the eggs to temper. Continue to whisk slowly in the remaining cream mixture. Pour back into the saucepan.
Cook mixture over medium-low heat, constantly stirring, for about 5 to 10 minutes or until they are thick enough to coat the back of the spoon. If you have a cooking thermometer until it reaches 170 degrees. If overcooked, the mixture will curdle. Strain the mixture if necessary.
Pour custard mixture into a bowl, cover with cling film touching the surface, and let it cool to room temperature. Refrigerate for a minimum of 6 hours or overnight, then freeze according to your ice cream maker directions. When the ice cream begins to firm up, add the loose green tea, and continue churning. Place the ice cream in a container in the freezer and let it firm up before serving.
Japanese Green Tea Ice Cream https://cultureatz.com/japanese-green-tea-ice-cream-recipe/