In a bowl mix together ground beef, sausage, dried parsley, dried onion, sage, and salt. Form into meatballs about 1 1/2 inches in diameter (about 30 meatballs). Place mushrooms, onions, water, and gluten-free soy sauce into the Instant Pot. Add the meatballs. Cook on high pressure for 35 minutes. Once time is up quick release the pressure.