In a small saucepan, whisk the egg yolks, sugar and sea salt into a smooth paste. Gradually whisk in the cream and milk until fully incorporated, then add in the Earl Grey tea bags.
Place the saucepan over a low-medium heat, stirring continuously for 8-10 minutes, until it thickens slightly. The custard should read 75°C (167°F) on a kitchen thermometer.