Set pressure cooker to "sear", add butter, adjust time to 10 minutes, and press "start/stop". When melted, add onions and bell pepper and cook until soft and translucent.
Add corn and potatoes. Season with sea salt and fresh ground black pepper.
Close and lock lid, set pressure cooker to "steam/veggies", adjust time to 10 minutes, and press "start/stop".
When done, quick release and make sure all pressure is released before opening lid. Carefully open lid and set to "sear", adjust for 20 minutes, and press "start/stop".
In a bowl, add cornstarch with water and mix. Add to cooker and stir.
When boiling, incorporate cheese and half & half slowly, stirring constantly. Season to taste sea salt and fresh ground black pepper.