Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel the honeynut squash and Yukon gold potatoes, then dice them into uniform 1/2-inch cubes.
In a large mixing bowl, whisk together the olive oil, smoked paprika, garlic powder, sea salt, and black pepper.
Add the cubed seitan, squash, potatoes, and rinsed black beans to the bowl, tossing thoroughly to ensure every piece is coated in the spice oil.
Spread the mixture across the prepared baking sheet in a single layer, ensuring enough space for the vegetables to roast rather than steam.
Roast for 25 to 30 minutes, flipping the hash with a spatula halfway through, until the squash is tender and the seitan edges are crisp.
Remove from the oven and immediately sprinkle with nutritional yeast and fresh chopped parsley before serving hot.