Combine the bison meat ingredients in a large bowl. Stir everything together until the ingredients are completely incorporated. Then use your hands to roll out small inch-wide balls of meat. Place the raw meatballs into the bottom of the Instant Pot chamber.
In a small bowl, whisk together the ingredients for the plum bourbon sauce until a thick sauce forms. Pour the sauce over the meatballs. Pour one cup of water into the Instant Pot and gently mix the meatballs around so that the water is evenly dispersed.
Place the lid onto the Instant Pot so that it locks. Set the Instant Pot to “pressure cook” mode on the “normal” setting. Set the timer for 10 minutes. When the Instant Pot reaches pressure, the timer will start.
Let the Instant Pot depressurize naturally over 15 minutes or carefully perform a quick release. Use a slotted spoon to remove the meatballs from the sauce and set aside.
Press “cancel” on the Instant Pot to reset the cooker. Then turn the Instant Pot onto “saute” mode on the “more” or “high” setting. Let the sauce simmer for about 30 minutes, stirring occasionally, until the spoon leaves streaks across the bottom of the Instant Pot and the sauce is nice and thick.
Return the cooked meatballs to the Instant Pot. Return the Instant Pot to the “keep warm” setting. Stir the meatballs around until they are covered in sauce and heated back to your desired eating temperature – about 5-10 minutes. Enjoy!