Originated sandwiches container for tea -- sweet! (7)
I believe the answer is:
compote
'sweet' is the definition.
(compote is a kind of sweet)
'originated sandwiches container for tea' is the wordplay.
I cannot quite understand how this works, but
'container' could be 'pot' (pot is a kind of container) and 'pot' is located in the answer.
The remaining letters 'come' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for compote that I've seen before include "Stewed fruit dish" , "Fruit salad" , "Fruit cooked in syrup" , "dessert dish" , "Come top (anag.)" .)