Add the rice, butter, and salt to the insert of an Instant Pot. Add 1 cup of cold water.
Set the valve to “sealing” and set to 4 minutes on high pressure.
Once the pot has come to pressure and the timer beeps that the cooking time is done, let the Instant Pot do a natural pressure release for 12 minutes.
Flip the valve to “venting”. Once the pin drops to indicate all the pressure has been released, open the lid.
Fluff the rice with a fork.
Add the lime juice and the lime zest. Mix well.
Fold in the cilantro and serve immediately.