Add chicken or vegetable stock to a medium saucepan.
Bring to a boil over medium high heat.
In a separate bowl, mix together the milk and flour until flour is dissolved.
Slowly pour the milk mixture into the boiling broth and whisk to completely combine.
Stir in the mushrooms and and spices.
Reduce the heat to medium and let it come to low boil, stirring constantly.
Continue to boil for 3 minutes or until thickened.
Remove pan from heat.
Store in an airtight container in the refrigerator for up to 7 days if not using right away
Remember this is a condensed soup and is not meant to eat directly. Be sure to dilute it with chicken or vegetable broth if you'd like to eat it as a soup.