Short root, large amount that's often served with nachos (4,5)
I believe the answer is:
sour cream
'with nachos' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'short root large amount that's often' is the wordplay.
I cannot quite see how this works, but
'amount' could be 'ream' (ream is a kind of amount) and 'ream' is located in the answer.
This explanation may well be incorrect...
'served' acts as a link.
Can you help me to learn more?
(Other definitions for sour cream that I've seen before include "dip" , "cooking ingredient" , "Rich savoury food" , "Fermented dairy product" , "salad dressing" .)