I took a lot of liberties with this recipe, but it still came out really great. I would make some slight changes next time, but nothing big.
The crust: I only had regular whole wheat flour but it came out fine. As per other suggestions I added approx 1 T oil and 2 T water than was called for in the recipe. Next time I would add just a bit more salt (1/4 tsp?) and some garlic. The texture was great, but a bit bland for me.
The filling: Used my mandolin to slice the potatoes (1/4 inch, skin on!) and onion (1/8 in) so that part was really easy. I tossed the potatoes in oil, pepper, and salt but skipped that step with the onions - they were still delicious. It was 86 F and HUMID. The AC was off (May just started!) making it about 95 in the kitchen. I the extra roasting step and just rolled out the dough and arranged the veggies/cheese.
It took about 60 mins to fully cook at 375F. The veggies were plenty cooked at 50 mins, but the crust looked like it needed a bit longer.
I liked the skins on the sweet potato slices - adds fiber and flavor. Pre-roasting the veggies would have turned them into mush and ruined the dish so I was glad I skipped it.