On a flat surface, lay chicken breasts out and slice in half horizontally. Pound out breast pieces to ?-inch thick. Place chicken in a large mixing bowl with oil, Italian seasoning, salt, and garlic. Coat chicken in marinade.
Set pressure cooker to "sear", add oil, and press "start/stop". When oil is hot, brown chicken with marinade. Cook in batches, if needed. Add chicken stock, close and lock lid, set pressure cooker to "poultry", adjust time to 3 minutes, and press "start/stop". When done, quick release and make sure all pressure is released before opening lid.
Carefully open lid and set pressure cooker to "sear", adjust time to 20 minutes, and press "start/stop". Add seasoned salt, heavy cream, and cream cheese, and whisk. Simmer about 5 minutes.
Add cheese, sun-dried tomatoes, and spinach. Simmer until spinach wilts. Ladle over your favorite pasta and top with fresh oregano.
