So I've been perusing /u/ramen_lord's awesome book for my next ramen project. I'm going with a simple chicken chintan ramen, Tokyo style. My question is: how can I add the dashi ingredients (I wanna use kombu, katsuobushi and shiitake) at the end of the cook if I'm using a pressure cooker? I don't want to boil these ingredients, for obvious reasons, so I'm at a loss.

Should I just make and overnight dashi and 'fortify' the broth later with it, separately? Or is there a simpler method that I'm overlooking (could not find the answer in the book)? I used to do my own twist on tonkotsu ramen on the stove top, by using both ichiban and niban dashi during the whole cook time (except during the bones preboil to skim impurities), but I'm thinking I could have been losing some flavour this way.

TiA!