Lay it on thick like Hollandaise at brunch (7)
I believe the answer is:
overegg
'lay it' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'on thick like hollandaise at brunch' is the wordplay.
I cannot quite see how this works, but
'on' could be 'over' (over can mean on top of) and 'over' is found within the answer.
'like' could be 'eg' (I've seen this in other clues) and 'eg' is located in the answer.
A single letter 'g' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for overegg that I've seen before include "Something to do with pudding" , "Embellish unreasonably" , "Hugely exaggerate" .)