Set the Instant Pot to Sauté mode and add the extra virgin olive oil to the inner pot.
Once the oil is shimmering, add the diced yellow onion and sliced cremini mushrooms, sautéing for 3 to 4 minutes until the onions are translucent.
Stir in the minced garlic, dried thyme, and dried oregano, cooking for 30 seconds until the aromatics are fragrant.
Season the chicken breast with sea salt and black pepper, then place it into the pot on top of the vegetables.
Pour the condensed cream of chicken soup over the chicken, ensuring the meat is well-covered to prevent drying out.
Secure the Instant Pot lid and set the steam release valve to the Sealing position.
Select Manual/Pressure Cook on High for 8 minutes.
When the timer finishes, allow the pressure to release naturally for 5 minutes before performing a quick release for any remaining steam.
Carefully open the lid and stir in the heavy whipping cream and baby spinach, allowing the residual heat to wilt the spinach into the sauce.
Serve the chicken hot, generously ladled with the creamy herb sauce.