Set Instant Pot to saute and add olive oil. Once hot, add onion and saute until translucent, about 7 minutes.
Add pork to Instant Pot and brown on all sides for 1-2 minutes each.
Leave pork in Instant Pot and add garlic, diced tomatoes, tomato paste, chili powder, chilis, bay leaves, oregano and broth. Secure lid and set the vent to sealing. Change the setting to meat/stew and increase the time to 1 hour. When done, release the vent manually.
Remove pork from Instant Pot and discard bone (if applicable) and any fatty bits. Let cool enough to handle.
While pork is cooling, add sauce to a blender and puree until smooth.
Return the sauce to Instant Pot and set to keep warm. Add the cashews.
Shred the pork by hand using forks to pull apart or shred using stand mixer and whisk attachment.
Return pork to Instant Pot and stir to combine all ingredients. Serve in bowls and add lime juice and season with salt and pepper to taste. Top with avocado, fresh diced red onions, radish, cabbage slaw, and cilantro, optional.