Add all ingredients from the "to cook the chicken" section to the inner pot of the Instant Pot, starting with the chicken breast and layering the rest of the ingredients. No need to stir.
Close the lid, and make sure the valve is set to "sealing".
Press the Pressure Cook or Manual button and use the +/- buttons to set the timer for 15 minutes.
Once the timer beeps, do a 10 minutes Natural Pressure Release, then open the valve to release any remaining pressure. When the pin drops, carefully open the pot.
Use chicken tongs to remove the chicken breasts to a large bowl and shred them using two forks.
In a small bowl, stir together the cornstarch and water until smooth.
Click on saute and add the mixture to the pot. Cook for several minutes, stirring often until the sauce thickens.
Toss the shredded chicken with as much of the sauce as you'd like and serve topped with cilantro and jalapenos.
