Make the edamame guacamole, if using: If you're making my homemade edamame guacamole, I like to make that first (or even up to a day in advance) so it has time to get cold in the refrigerator! You can skip this step if you're using traditional guacamole or diced avocado. Blend the black bean taco crumble mixture: Add the black beans and chopped mushrooms (if using) a food processor (or a blender can work). Pulse until it's well chopped. If it becomes a puree, don't worry. Mine was pretty close to that state and it still cooks up nicely. You may need to stop the food processor a few times to get all the mushrooms finely minced.
Heat and season the black bean mixture: Heat a large nonstick skillet over medium heat for 1-2 minutes and spread the black bean mixture over the flat surface of the skillet. Sprinkle on the spices, stir well, and flatten the mixture once more.
Cook the black bean taco crumbles: Let the mixture cook for about 10-15 minutes or until it looks sufficiently dried out. Definitely stir it every few minutes, flipping as much of it as possible so it gets evenly dried out and browned. There's a lot of moisture in the mushrooms, which is why it takes a while. You'll know it's done when you can easily break up the mixture with your spatula and it looks more dried out and less like cookie dough. Once it cools, you could crumble it further, or you can simply just sprinkle medium-sized chunks of it onto your bell pepper nachos.
Make the cheese sauce: Blend up your vegan nacho cheese sauce ingredients (unless using store bought vegan queso or vegan cheese shreds) until smooth and creamy. Taste, make any necessary adjustments, blend again if you add anything, and set aside. You can warm it when you're ready to serve, if you like.
Cut the mini bell peppers: Take a washed mini bell pepper, slice off the top, and then slice is lengthwise so you can two triangular shapes, much like a narrow tortilla chip. Scrape out any remaining seeds. If you'd like, you can using a small paring knife to remove the thin strip of membrane, but I don't even notice it underneath all the delicious toppings. Repeat with as many bell peppers as you'd like to use.
Assemble bell pepper nachos: If the crumbles are done, it's time for assembling! You can do this any order you like, but this is how I usually do it: lay the sliced mini bell peppers inside facing up on a large plate, crumble some of the cooked black bean mixture over the top of them, dollop the edamame guacamole with a small spoon, fill in some of the gaps with the pico de gallo, and give everything a real good drizzle of the vegan nacho cheese sauce! You can do a double drizzle if you want; I usually do. Top with anything else you want to use, like cilantro, green onion, tofu sour cream, hot sauce, anything!
Storage: The individual toppings—guac, black bean taco crumbles, cheese sauce—keep well in separate airtight containers in the refrigerator for up to 5 days. Cut bell peppers usually get soft, so I'd wait to cut those till you're ready to serve.