I'm not an expert on mushrooms but I tried foraging this past summer and was very surprised to find a completely edible fungus that is quite similar to chicken in it's taste. I found it growing on a large tree and immediately identified it as the proverbial "chicken of the woods" and plucked it off. The taste is very similar to chicken and it would definitely work well in a pasta as a substitute for chicken. I'm not sure if you're able to find this but just thought I'd add this option for you to think about. The technical name of the fungus is Laetiporus and you can find more info on it by googling.