Melt 1 tablespoon dairy free butter in a skillet over medium high heat.
Add the mushrooms and sauté for 10 to 15 minutes. Set aside.
In a medium saucepan melt the remaining ½ cup butter over a medium-low heat.
Add in flour and whisk together until well combined.
Add vegetable broth and dairy free milk. Whisk until smooth which will be about 1-2 minutes.
Season with salt, pepper, garlic powder and onion powder.
Bring to a simmer and cook until it begins to thicken, About 3-5 minutes, If it becomes too thick you can add a little more dairy free milk.
Add the sautéd mushrooms. Heat through.
Remove from heat and serve or allow to cool completely if storing.
Store in airtight container in refrigerator.