Heat oven to 425. Line a large rimmed metal baking pan with parchment paper, then toss the potatoes and peppers in the oil until evenly coated.
Toss the potatoes and peppers in chili powder, black pepper, and salt, then roast for 10 minutes. Flip, then roast another 10 minutes or until the potatoes are tender.
When the potatoes are almost done, heat the tortillas in a skillet.
Once the potatoes and peppers are tender, toss in the black beans and corn, then place the pan back in the oven for one minute, to warm the beans and corn.
While the beans and corn are in the oven with the potatoes and peppers, spread the mashed avocado over the tortillas, seasoning with salt.
Remove the potato mixture from the oven, then distribute between the two tortillas.
Top with pepitas, lime juice, shredded lettuce, cilantro, and hot sauce, if you wish.
