Thanks Pedro, firstly when bringing appetisers (5)
I believe the answer is:
tapas
'appetisers' is the definition.
(I've seen this before)
'thanks pedro firstly when' is the wordplay.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'firstly' suggests taking the first letters.
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
The initial letter of 'pedro' is 'p'.
'ta'+'p'+'as'='TAPAS'
'bringing' acts as a link.
(Other definitions for tapas that I've seen before include "The Spanish scoff" , "Spanish eats" , "Spanish appetiser" , "snack" , "sort of Spanish bar" .)