When oil is hot, add carrots, celery, and onions and sauté.
Add mushrooms and garlic.
Add 1 can of the chicken stock, thyme, sea salt, freshly ground pepper, red pepper flakes. Add cubed potatoes and corn.
Close lid and lock. Set to "soup" and adjust for 4 minutes.
When done, natural release for 35 minutes. Afterward, quick release until all pressure is released.
Set cooker to "slow cook" and simmer soup, then puree with extra stock. Gradually stir in remaining can of chicken stock. Stir in half and half to soup.
