Finished digging? My congratulations! (4,4)
I believe the answer is:
well-done
This clue might be a double definition.
'finished digging?' is the first definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives can sometimes define each other.
'my congratulations' is the second definition.
(Other definitions for well-done that I've seen before include "No pink inside?" , "Congratulations - cooked right through" , "Congratulations - certainly not rare!" , "Bravo" , "Thoroughly cooked or meritoriously accomplished" .)