Using sauté setting - add oil and sausage to Instant Pot. Cook for about 5 minutes, until fat is rendered and edges are crisp.
Meanwhile - Add grits to oven-safe glass bowl. Add milk and chicken stock to glass bowl and whisk together. Set aside.
Add onions to pot and sauté for about 3 minutes, until softened and translucent. Then add garlic and continue cooking for one minute.
Next, add wine and cook for about five minutes, making sure to scrape up all the fond (brown bits) from the bottom of the pot. Add tomatoes and creole seasoning to pot and mix well.
Add 3-inch trivet to Instant Pot, then place oven-safe glass bowl with grits on top of trivet. Lock lid and cook for 10 minutes at high pressure. Then allow pressure to release naturally (about 10 minutes).
Carefully remove glass bowl from Instant Pot. Add butter to grits and whisk well, making sure to break up any clumps. Then cover until ready to serve.
Switch Instant Pot back to sauté setting. Add thyme, parsley, and green onions to pot and mix well. Bring up to a boil. Then add shrimp and cook for about five minutes (only until shrimp have turned pink throughout). Keep them moving, every 30 seconds or so, to ensure they cook evenly.
Just before shrimp are fully pink, add cream and mix well. Then switch to warm setting.
Spoon grits into a serving bowl and top with shrimp and sauce. Enjoy!