Extremely nice lunch forged deep international connection (7)
I believe the answer is:
Here is my best explanation:
'deep international connection' is the definition.
(informal term for the Channel Tunnel)
'extremely nice lunch forged' is the wordplay.
'extremely' suggests removing the centre.
'forged' indicates an anagram.
'nice' with its middle taken out is 'ne'.
'nelunch' with letters rearranged gives 'CHUNNEL'.