Feature in garden party with superb sandwiches (7)
I believe the answer is:
dogwood
'feature in garden' is the definition.
(type of tree which might be grown in a garden)
'party with superb sandwiches' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'with' becomes 'w' (abbreviation).
'superb' becomes 'good'.
'sandwiches' means one lot of letters goes inside another (to sandwich is to block something in).
'w' put inside 'good' is 'gwood'.
'do'+'gwood'='DOGWOOD'
(Other definitions for dogwood that I've seen before include "Wild cornel" , "Shrub with dark red 5s" , "Flowering tree" , "grows wild" , "Flowering shrub" .)