Dry the chicken breasts with paper towels. Place into a large bowl and season with the packet of taco seasoning. Set aside.
Place a rack into the Ninja Foodi/Instant Pot. Pour in one cup of chicken stock or broth. Spray the rack with cooking spray. Place the chicken on top of the greased rack.
Pour the salsa on top of the chicken. Try to make sure most of the salsa stays on top of the chicken and not too much falls to the bottom.
Pressure Cook on HI for 15 minutes. Your electric pressure cooker will take anywhere from 7 to 10 minutes to come to pressure. When the pressure cooking is done, allow for Natural Release for 15 minutes, then move the pressure release valve over to Vent to Quick Release the remaining pressure.
Place chicken into a large bowl and shred with two forks.
STORAGE: Store leftovers in an airtight container in the refrigerator for up to 4 days, or in the freezer for up to 2 months.