In Mockito there is option to verify if mock method has been called, and specify timeout for this verification (VerificationWithTimeout), for example:
VerificationWithTimeout
There is no equivalent in Spock. (PollingConditions can only be used for conditions, not for interactions.) The closest you can get is to add a sleep() statement in the then block:
PollingConditions
sleep()
then
when: ... then: sleep(200) (1.._) * mock.baz()