Gracious and laid-back, having a drink (7)
I believe the answer is:
cordial
'a drink' is the definition.
(cordial is a kind of drink)
'gracious and laid-back' is the wordplay.
'gracious' becomes 'cor' (both are exclamations of surprise).
'and' is a charade indicator (letters next to each other).
'back' shows that the letters should be reversed in order.
'laid' in reverse letter order is 'dial'.
'cor'+'dial'='CORDIAL'
'having' is the link.
(Other definitions for cordial that I've seen before include "drink with a fruity flavour" , "Hearty - drink" , "Warmly welcoming to the drink" , "Affable type of sweet drink?" , "Agreeable - drink" .)