Turn on Saute mode on high. When the display reads, 'hot, add oil and chopped onions, garlic and ginger. Saute for 1 minute.
Add water, all sauces and seasoning listed under "sauce". Stir and add the frozen veggie meatballs. Cancel Saute. Close lid. Press Manual or Pressure Cook at 3 mins.
When 3 minutes is up, manually release the pressure by turning the vent to 'venting' position in DUO, or, Press down the pressure release button in ULTRA. When the pin drops, open the lid.
After Pressure Cooking
Turn on Saute. Stir together the cornstarch slurry by mixing cornstarch with water. Mix till you get a smooth milk-like consistency. Add a little as a time, while stirring. Stop when the sauce thickens to your desired level.
Garnish with sliced spring onions and serve warm
If you have regular soy sauce instead of Tamari, check for seasoning after adding the soy sauce, and add an extra pinch of salt or 1 tsp of soy sauce.