After Stella, tipsy Lord Lieutenant spills the beans (5,3)
I believe the answer is:
split pea
'after stella' is the definition.
The definition suggests a singular noun which matches the answer.
'tipsy lord lieutenant spills the beans' is the wordplay.
I cannot quite understand how this works, but
'tipsy' could be 'lit' (I've seen this in another clue) and 'lit' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for split pea that I've seen before include "Dried vegetable" , "What's ready to add to casserole" , "Pulse" , "A stipple (anag.)" .)