In a large saucepan melt butter over a medium-low heat.
Add in the sliced mushrooms and cook over medium high heat until the mushrooms are soft and have released must of their liquid (5-7 minute).
Stir in the chicken broth, salt, pepper and garlic powder. Bring the mixture to a low simmer.
In a small bowl, whisk together the flour and milk.
Stir this mixture into the sauce pan.
Bring to a simmer and cook until it begins to the soup begins to thicken (3-5 minutes).
Remove from heat and allow to cool completely.
Store in airtight container in refrigerator until ready to use. Enjoy!
Notes
You can use any type of mushrooms for this recipe. I use button mushrooms but any will work in this recipe. This recipe makes approximately 2 cups which is approximately the size of a regular can of cream of mushroom soup (10.5 ounces). Refrigerate until ready to use in an airtight container for up to 5 days.