Prep the pork. Slice the pork thin and pat it clean. Toss it with the paprika, all-purpose seasoning, oregano, onion powder, garlic powder, chili powder, olive oil, Worcestershire sauce, and salt.
Tenderize and coat. Sprinkle in the cornstarch and baking soda and mix well. Let it sit for 10 minutes.
First fry. Heat oil in a pan until hot. Working in batches so you don't crowd the pan, fry the pork for 4–5 minutes. Remove and let rest for 5 minutes.
Second fry. Fry the pork again for about 5 minutes, until deeply golden and crispy. Watch closely so it doesn't burn.
Make the sauce. Whisk together the brown sugar, ketchup, honey, salt, soy sauce, and rice vinegar.
Sauté the vegetables. Drain most of the oil from the pan, leaving a thin layer behind for flavor — don't wipe the pan clean. Sauté the onion, green pepper, and pineapple (if using) until just softened.
Build the sauce. Pour in the sweet and sour sauce and let it bubble and thicken until slightly caramelized.
Combine. Add the crispy pork back into the pan and toss for 1–2 minutes, just until the sauce coats the pork. Don't overcook — you want the pork to stay crispy.
Serve. Spoon over rice or noodles.