In an Instant Pot on Saute mode, add the oil and onions.
Sautee for 2-3 minutes until browning starts.
Add shredded cabbage and saute for another minute or two.
Add chicken, stock, salsa, garlic powder, and salt (you can add more salt later)
Switch Instant Pot to soup mode. Cook for 16 minutes.
Allow steam to release either naturally or you can turn the release valve (careful!).
Optional: add sour cream or a dash of heavy cream to make the soup creamy. You can also top with some shredded cheese. Nutrition facts do not reflect these additions.