Dinner -- almost a success

I made Shiitake and Sweet Pea Risotto from the latest Cooking Light Magazine.  I used vegetable broth, and didn't have fresh thyme, so I used dried.  The dish turned out really creamy -- my husband was surprised it didn't have any type of milk or cream in it.  We were both underwhelmed with the shiitake mushrooms, though.  They were mostly tasteless, and kind of chewy.  I'm unfamiliar with them, so did I have a bad bunch of mushrooms?  Or is that the way it was supposed to be?  Next time, I'll use the baby bellas that I love.