You can manage this by creating new internal transfer. Picking Type : Internal Expense, Source Location : Stock, Destination Location : Expense Location .
By this you can manage if you have multiple department and which department consume more tea(by creating separate location).
Unfortunately, the expense module is not linked or affecting the inventory quantities.
I recommend to sell the product to a virtual customer "Internal Consumption" so the quantities can be reflected in the inventory moves.
the only side effect to this approach that you have to sell the items for a price of Zero.accordingly it will not affect the analytic account value related to the process :(
Hope this helps!