Boil UFC Oat Milk with earl grey tea bag and let the tea infuse into the oat milk.
Then remove tea bags and add in sugar. Let it simmer until sugar dissolved.
Mix egg yolk and corn flour together and add 1 tbsp of infused oat milk.
Then pour in egg yolk mixture and quickly give it a whisk to prevent it from cooking.
Keep stirring it over medium heat until it is thicken.
Once thicken remove heat and add in butter.
Mix until butter is fully blend in well.
Boil a pot of water and boil the bobas for about 4 to 5 mins then strain it.
Boil brown sugar and water together until it is slightly thicken then mix cooked boba in.
Pipe in earl grey tea custard into the readymade tart and place brown sugar boba on top.