If you want to use russet potatoes be sure to peel them. Otherwise keep the peels on the Yukon or baby reds for extra nutritional benefits
I've found that patty pans, delicata, daikon, and radish are all great in this queso. The most neutral in flavor is the daikon, but all taste great in this recipe
Chickpea Miso can be found in Health Food Stores like Natural Grocers. Otherwise you can use any variety of miso you have access to
The Tapioca Starch helps this sauce become more thick, stretchy, and gooey. It can be found in most supermarkets and is easily found in Asian or international grocery stores
Nutritional Yeast Flakes can be found in most health food stores like Natural Grocers, Whole Foods, ordered online, or at vegan markets.
It is filled with umami flavors with a slightly cheesy, nutty, depth that is an incredible spice. It is one of the most under rated spices in the culinary community and is considered a vegan staple since it helps create incredible flavors.
While it is recommended you DO NOT SUBSTITUTE IT- I understand it is not a common ingredient.
If you must substitute it, replace it with equal parts miso paste, an extra tsp mustard, an extra drop of liquid smoke, and consider increasing your peppers/spice. Taste as you go!
Consider using Beta Carotene Capsules.
It naturally colors your queso into an orange hue without altering the flavor. Often recipes will call for tumeric to color their sauces, however it can disturb the flavor.
Beta Carotene Capsules are found in your supplement isle at most grocery and health food stores.
If you don't add it your queso will be beige in color rather than the bright orange you see in the images.
Truffle salt helps adds deep umami to the sauce. You can find it at farmers markets, order it online, or find it at specialty cooking stores.
Other things that would work here would be msg, mushroom seasoning, and...
-In a Pinch- use standard sea salt!