I make stock in a pressure cooker.
Roasted carcass or even two carcasses (I can get them for a few pence at my farmers market if I order a week before.
Bung in oven to roast.
Drain off fat or shmaltz for cooking roasties or in fact browning any meat.
Put roasted bones, plus celery, onion, carrot and bay in pressure cooker. Top up with water and cook half an hour.
When cool, strain off the liquid.
The bones will be so soft they will crumble and the liquid will set to a jelly.
It can be frozen in portions if you want.
I wouldn't add anything like star anise as it alters the flavour of the stock to much.
For me anyway, this can be done, if need be, at the stage the stock is added to a recipe.
I wouldn't want star anise in a simple chicken noodle soup.