Set pressure cooker to "sear", add oil, adjust time to 15 minutes, and press "start/stop". When hot, add celery, onions and turkey, breaking up meat until browned.
Add red wine vinegar, diced tomato, tomato paste, vegetable stock, Italian seasoning, red pepper flakes, sea salt, and fresh ground black pepper.
Close lid and lock, set to meat/stew, and adjust for 10 minutes.
When done, quick release and make sure all pressure is released before opening lid. Carefully open lid and add mushrooms. Close again and set for another 5 minutes.
Once done, quick release the pressure again and make sure all pressure is released before opening. Carefully open and serve immediately over spaghetti squash topped with basil.
