Sprinkle one packet of the Sazon Goya (or 1 1/4 teaspoons of seasoning salt) over both sides of the flank steak. Heat the tablespoon of oil in an Instant Pot set to SAUTE. When the oil is very shimmery lay the flank steak down in it carefully. You may need to cut the steak in half to fit. Don't move the steak for 4 minutes. Use tongs to flip the steak to sear the other side for another 4 minutes. Repeat with the other half if you needed to trim it to fit. After searing the steak, use tongs to transfer it to a plate.
If the pan is dry, add the additional teaspoon of peanut or canola oil, then add the green peppers and onions along with a pinch of salt. Saute, stirring frequently, until the onions and peppers have a touch of colour around the edges, about 3 minutes. Stir in the garlic and cook just until fragrant, about 30 seconds. Stir in the tomatoes, beef broth, wine, remaining packet of Sazon (or last 1 1/4 teasoons of seasoning salt), olives, capers, raisins, kosher salt, and coarse black pepper, return the flank steak to the pot, pressing to submerge the meat as much as possible. Fix the Instant Pot's lid in place, be sure the vent is in the closed position, and set to High Pressure manually for 70 minutes.
After the time is up, release the pressure by carefully venting, remove the lid, use tongs to scrape anything off of the top of the steak and transfer the steak to a cutting board.
Hold the steak down at one end with a fork. Poke another fork into the steak near the anchoring fork and pull away, down the length of the steak, shredding the steak into long, thin, ropy strips. Repeat until the whole steak has been shredded. Return the shredded meat to the Instant Pot and toss to distribute everything evenly. Serve hot, warm, or room temperature on rice or noodles. If desired, garnish with chopped, fresh cilantro or parsley and some fresh lime wedges for squeezing over the dish.