I baked it for 20-21 minutes and it is a little dry, so 18 would likely have been better. The wedges could also have been a bit taller: I halved the recipe and should have formed them out to less than an 8” disc. Will be good with coffee or tea, though.
I used baby Yukon gold potatoes and they needed significantly longer to cook. I’d estimate the time to cook the veggies to be an hour plus rather than the 30 or so. Also, added salt after each addition to the stew and a little dried thyme for the last 20 minutes or so.