How to use Awaitility to repeatedly call a condition check with variable execution time?

Question

I would like to use Awaitility to assert that a condition returns true within 30 seconds. However, the condition check itself takes a different amount of time (sometimes instantly, sometimes 5 seconds, etc.). I want to start the next condition check as soon as the last condition check has finished, but not sooner. How should I do this using Awaitility?