First of many disrupting Buddhist monk’s current feast (10)

'feast' is the definition.

'first of many disrupting buddhist monk's current' is the wordplay.
'first of' suggests taking the first letters.
'disrupting' is an insertion indicator (inside letters 'disrupt' the flow of outside one).
'buddhist monk's' becomes 'lamas'.
'current' becomes 'tide' (I've seen this before).
The first letter of 'many' is 'm'.
'm' put into 'lamas' is 'lammas'.
'lammas'+'tide'='LAMMASTIDE'