Harissa sweet potato wedges

I've tried sweet potato fries a few times but they always come out a little mushy. What am I doing wrong? I want them firm but crispy.

Enjoyed these both as a low fat evening snack dipped in yoghurt & harissa, then the next day chopped-up and served cold in my packed lunch of puy pentils, tomatoes, celery and sliced radishes, tossed in more of the yoghurt & harissa mix.

I made these last night. They were delicious. I added a bit of olive oil and some dried chilli, which gave these even more of a kick. Served with soured cream. So easy and healthy. Will definitely be making again.

I agree w/ previous comments that more harissa is needed to give this some kick (or not, if one wants to make it kids-friendly). It also helps to add a few splashes of olive oil to the paste to make spreading it over the potatoes easier. Really liked the sour cream + chives dip alongside, though.