Food burn happens when the food is stuck to the bottom of the pan. Deglazing is very important as it helps to avoid Food burn while cooking in IP. After sauteing the vegetables, add 1/4 cup of water to the instant pot, use a long ladle and scrap bottom of the pan nicely, stir well. When deglazing is done, it clears the bottom of instant pot from any stuck food particles while sauteing, which also adds nice flavor to the dish.