The mechanism for this is supernatural
Let's try it this way. First, while I think we are already on the same page here, these are the two main things I would expect you to agree to. If the answer for both of these is 'yes', you can just skip ahead. Otherwise, let me know because it would mean we have different understandings of some of the premise and this whole conversation is probably a waste of our time.
1. When god created the universe, could he have chosen to create it any other way?
2. Before god created the universe, did he know exactly how everything would happen?
Okay.
So, if I decide to eat a sandwich we could totally break it down and say that first I decided to get up, and then to go to the kitchen, and then to open the fridge, and then to get out the mayo, and then to... and so on, all the way to each individual bite and chewing and whatnot.
But we don't. We just say that I decided to eat a sandwich. What I'm saying is that in this scenario it would be most accurate to say "god made the universe and all the things and events in it". Any specific part of those things or events are still, at a fundamental level, just part of god's one decision to make the universe.
Saying that I made the choice to eat a sandwich but on bite number 32, mastication number 192, one of my molars made a choice to apply pressure to the turkey is silly. I ate the sandwich.
God's act of creation was a one-time choice, that incorperated the entire universe not only in substance but in events - especially if you don't think god is bound by time.
