In Gitlab CI, is it possible to trigger the following job prematurely?

For example,

The first job in my pipeline is to build an Amazon AMI by using Packer
However it takes 5min to spin up infrastructure and then a further 5min to create the AMI and destroy infrastructure.

I was wondering if instead of waiting for the full 10 min before continuing with the pipeline, to trigger the next step prematurely (the remote machine could trigger the next step before completing and creating the AMI).

I know I can pass variables on to the remote machine by set > all_vars; grep CI.*= all_vars > ci_vars and then passing ci_vars over to the remote machine. Would that help? As far as I understand, in there are the required tokens to launch triggers. I only see docs about triggering pipelines, not much on triggering jobs.