Now, this is on the house (7)
I believe the answer is:
present
'now' is the definition.
(I've seen this before)
'on the house' is the wordplay.
I cannot really understand how this works, but
'on' could be 're' ('on' can be mean 'with reference to') and 're' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'this is' is the link.
Can you help me to learn more?
(Other definitions for present that I've seen before include "It is given" , "A Christmas gift" , "In attendance with award?" , "gift > offer" , "in a particular place" .)