Great recipe! This is going to become a staple. Here's how mine went.
As others have noted, the cook time is way off. Easily double it for the potatoes. I poked holes with a fork to try speed up cook time. I took the chickpeas out and put them back in towards the end.
I actually wanted a thick sauce and had no unsweetened milk on hand, so added a tbsp of vegan mayo, and then about 1/3 tsp of water. I'm also not into using raw garlic in sauces (bit harsh and good luck talking to anyone), and replaced that with garlic powder for roundness.
Finally, I wanted a little more crisp texture in here, so I added a very light bed of uncooked spinach on top of the potato but under the other toppings. Sliced Lebanese cucumber around the edges adds more texture, resets the palate and adds a little more bulk to the dish for the hungriest of us.