Pour the water into a heatproof container. Soak the gelatin powder.
Heat milk and the tea bag in the sauce pan until just before boiling. Cover with a lid and simmer for another 5 -10 minutes.
Remove the tea bag and turn down the heat to low. Add Step 1 and sugar. Mix to dissolve them. Please be careful not to boil.
Remove from the heat and cool. Transfer to a bowl and chill in the fridge for about 15 minutes. I usually cool it over ice water then put it in the fridge.
In another bowl, whisk the cold heavy cream until it is the same consistency as the mixture in Step 4.
Combine Steps 4 and 5. Mix evenly and pour into containers. Cover with plastic wrap and chill in the fridge again.
Decorate the top as desired (toppings not listed in the ingredients).
Story Behind this Recipe
The Theme of the Week this week was "Sweets Using Black Tea." I remembered that I made "Fluffy and Creamy Coffee Mousse" (Recipe ID: 284738), but I hadn't made a black tea version. It has different ingredients and uses a different process, so I uploaded this recipe here.
In Step 4, if it is too thick after chilling in the fridge, leave it at room temperature for a while and whisk gently until it has a thick consistency. You can also add spices that you like. I recommend chai tea flavouring. Of course, you can use loose leaves instead of a tea bag. Add 2-3 g of tea leaves to the saucepan, simmer then strain.