Combine cream and milk in a small saucepan and bring to a boil. Add jasmine tea leaves and turn off the heat. Cover with a lid and leave to infuse for 15 minutes.
Preheat oven to 300°F. Place 4 ramekins in a roasting pan or baking dish.
Whisk sugar and egg yolks in a medium bowl until thick and pale yellow, approximately 1 minute. Strain jasmine-
infused cream through a sieve. Whisking constantly, gradually add cream to egg mixture until well combined.
Pour mixture into the ramekins, filling them to about 3/4 full.
Place the tray in the oven; pour enough water into the pan to come about halfway up the sides of the ramekins. Bake for 40–45 minutes, until the custard is just set. Remove from the water bath and allow to cool completely.
Refrigerate the custard for 3–4 hours (overnight is best) before serving.