I made a soup in the IP today, a Mushroom Barley soup. It wasn't a one dish meal - I cook most mushrooms I put in dishes like this, or pasta dishes, using the ATK method of steaming the sliced or chopped mushrooms briefly, which pulls the excess water out of them, then brown them in a small amount of fat - this way, it doesn't absorb a lot of fat, when dry, and browning it and adding it towards the end gives the mushrooms a better flavor, which they keep, rather than releasing it all to the broth.
I started this by cooking some onions and a leek in some ghee, then added some celery and a carrot, and cooked a little longer. As I add to many mushroom dishes, some dried boletus mushrooms went in early, along with the soaking liquid. I also added a tb of white miso, and a tb of thin soy sauce for the salt, to the broth (soy seasonings always seems to go well with mushroom dishes). I added a quarter cup of red lentils, in place of a potato, in the original recipe, but also another quarter cup after the pressure cooking, when it was still a little thin, so those simmered 15 min after I added the browned mushrooms at the end, and it thickened up nicely.
Mushroom barley soup in IP, before last simmer. by
pepperhead212, on Flickr
Finished mushroom barley soup. by
pepperhead212, on Flickr