Wash and dice the mushrooms, then add them to a small saucepan with 1 tablespoon of oil.
Sprinkle the mushrooms with salt and saute for about 5 minutes, then add the garlic powder, paprika, black pepper, and plant-based milk.
In a separate container, mix together the starch and water and that to the mushroom mixture.
Stir continuously over medium heat until it bubbles and becomes thick.
Use it as you would a can of cream of mushroom condensed soup.
Notes
Potato starch gives it a slightly better texture and flavor than corn starch, but if you don't have it, corn starch will work well too.
You can also use unsweetened plant-based milk in this recipe.
Do not use vanilla-flavored plant milk.
You can also substitute the potato starch with white flour, but you will need to double the amount of white flour to achieve the same level of thickening power.