Plasterboard deeper than door frame

I’m in the process of applying 25mm insulated plasterboard but it’s deeper than the door frame. It obviously needs to be flush but unsure what would be the best thing to use to level it out or how I would even start without it looking crap. There is also a gap that varies in width between the edge of the plasterboard and frame (the wall wasn’t straight!) so this needs filling in too.

I don’t want to rip out the door frame or anything like that, so need some ideas on how to make it flush so it looks good and not a fudge job!

Get a door frame kit cut to correct width. My local timber/hardware would cut for free.
I know you don't want to do that but it's not expensive or time consuming. £30 and couple of hours on a go slow.
It's really the only way.

Quadrant bead and then architrave

Thanks @Wayners @aveatry Both great suggestions. I’ve now got good starting points so confident I can sort from here.