Peel and chop the onion and cut the mushrooms into thin slices.
Put water in the pan and bring it to a boil.
When it starts boiling add chopped onion and mushrooms into the pan.
Add garlic powder, mushroom powder, parsley, salt and yeast flakes.
Cover the pan with a lid and cook on medium heat for 10 to 15 minutes (or until the mushrooms are soft).
Add almond milk and soy sauce.
Mix the corn starch with water, pour it into the sauce and keep mixing so that there will be no lumps.
Cook for another 5 to 10 minutes, so that the sauce thickenss.
Serve with gnocchi, rice, mashed potatoes or pasta.