Set your Instant Pot to sauté mode. Heat the olive oil and add in yellow onion, celery and carrots. Stir until vegetables are soft. Add in minced garlic and saute until fragrant, about 2 minutes. Using a slotted spoon, remove vegetables and garlic and set aside.
Season pork with salt and pepper. Add pork and brown on sauté mode, 2 minutes on each side
Add softened vegetables and remaining ingredients, squeezing the San Marzano Style Tomatoes with your hands to crush them before adding them and their juices. Close lid.
Cook high pressure 45 minutes. Natural release, remove bay leaves, shred the pork with 2 forks. Serve over your favorite pasta or veggie noodles, or polenta.