In a bowl, mix together the ground beef, pork, minced parsley, dried onion, sage, mace, and salt. Once thoroughly mixed, form into meatballs about an inch in diameter.
Place mushrooms, onion, broth/coconut milk/water, and coconut aminos into the Instant Pot. Add the meatballs.
Close and lock the lid. Press the MEAT/STEW button and set cooking time to 35 minutes. Once the time is up, carefully quick release the pressure (using the instructions on page 7).
Using a slotted spoon gently remove meatballs and transfer to a serving platter.
Using an immersion blender or a high-speed blender, purée the cooked mushrooms, onions, and broth into a nice creamy gravy. If the gravy is too thick, add a little more bone broth/coconut milk/water until the right consistency is reached.