Heat the oil in pressure cooker pot for 2 to 3 minutes. Sauté the onion until tender, approximately 10 minutes.

Add the chicken, tomatoes, chili powder, salt and pepper.

Cover and lock lid in place. Select High Pressure and 12 - 15 minutes cook time (depending on how large your breasts are). When timer beeps, turn off and use a quick pressure release. *If using thawed chicken breasts reduce cook time.

Remove chicken from pressure cooker and shred. Return shredded chicken to pressure cooker pot and stir to combine with tomatoes and juice in pot.

Select Sauté and cook uncovered, stirring occasionally until all liquid is absorbed/evaporated.