Using asynchronous foreach

[headnoodle]

Just wanted to check what it means by asynchronous, unless I am doing something wrong, if I have a foreach with multiple steps within it then it seems to do the following

step1(item1)
step1(item2)
step1(item3)
step2(item1)
step2(item2)
step2(item3)

Is there a way to get it to work independently for each item in the foreach so depending on the time each item takes to process all the steps, item3 could have finished step2 whereas item1 is still on step1 as it is taking longer to process?

I guess the ideal situation would be to use the parallel functionality but I don't think I can do that with an undetermined amount of parallel steps I need to run, dependent on the input data. Or can I.....?