Heat oil in a large pan (or use Instant Pot on saute mode), and brown pork on all sides.
Remove pork and add onion. Saute onion until soft, about 4 minutes.
Place pork in slow cooker (can use Instant Pot on slow cooker mode.
Mix together onion with seasoned salt, 1 tbsp cumin, black beans, red salsa, and 1 cup of salsa verde. Mix well. Pour over pork.
Cook on low for 8-10 hours or high for 4-5 hours.
Remove pork and shred with two forks. Then, mix shredded pork back into ingredients in slow cooker.
Preheat oven to 400 degrees. Line large baking sheet with aluminum foil and spray with cooking spray.
In large bowl, combine pork mixture from slow cooker cheese, salt, pepper, chili powder and remaining 1 teaspoon of cumin.
Work in groups of about 5 corn tortillas. Place tortillas between two paper towels on a plate in the microwave. Heat for 30 seconds (this is important so that the tortillas don't break).
Fill each of the tortillas with about 1/4 cup pork & cheese mixture, and place seam side down on prepared baking sheet.
Spray tops of tortillas with baking spray. Cook for about 15 minutes, or until tops are golden and crispy.
Serve with salsa verde, sour cream, hot sauce, cilantro, or whatever other toppings you desire.