Clean the rice. Add the rice to a bowl, and add enough water to cover the rice. Swirl the rice around. Drain and repeat a few times until the water is clear.
Add the cleaned and drained rice into the Instant Pot. Add enough water until it reaches the 9 cup mark on the Instant Pot.
Add the ham bone and ginger pieces.
Close the lid on the Instant Pot and make sure the knob is on "Sealing". Choose the lid and press the "Porridge" button and change the timing to 22 minutes.
When the time is up on the counter, turn the Instant Pot off. Do a natural release by waiting for about 15 minutes before turning the knob from 'Sealing' to 'Venting'. Open the lid.
Press the “Sauté” button. Add the cooked ham and let it heat up for 1-2 minutes. Add fish sauce. Taste and adjust to your liking.
The recipe can be adapted for the stove top.
The 'cook time' indicated does not include the time it takes for the Instant Pot to go up to pressure.