Creating/Loading and object in a thread using ECS/Job System

I have just downloaded the new Unity 2018.1 release, and I would like to know if there is any possible way, using any method, to load a complex object into memory using any of the techniques and features now available?

I am trying to find solutions to load a complex prefab into memory at runtime. Currently, I am loading the object before the game starts, and just showing/hiding it, but this is very inefficent, and won't work for many objects.

I can use instantiate() but this is slow, and causes unity to freeze for a few seconds. What I really want is some way to instantiate an object in a background thread, is this possible in any way?