Set the Instant Pot to saute mode and heat the olive oil. Add the pork cubes and brown them on all sides for about 5 minutes. Season with salt and pepper during this step.
Add the diced onion, minced garlic, and sliced mushrooms to the pot. Stir and cook for 3 minutes until the onion softens.
Sprinkle in the dried thyme and stir to coat the ingredients. Pour in the chicken broth and scrape the bottom to release any browned bits.
Secure the lid and set the Instant Pot to manual high pressure for 25 minutes. Allow a natural pressure release for 10 minutes, then quick release any remaining pressure.
In a small bowl, whisk the heavy cream with the flour until smooth. Switch the pot to saute mode and stir the cream mixture into the stew. Cook for 2 to 3 minutes until the sauce thickens slightly. Adjust salt and pepper if needed.