Add butter to a large pot over medium-high heat and cook until melted.
Stir in the chopped carrots, celery, onion, and mushrooms.
Add the garlic and stir. Cook for 30 seconds.
Stir in the thyme, salt, pepper, onion powder, sage, and nutmeg. Mix until combined.
Whisk in the flour to combine and then let cook for another 2 minutes.
Add in your condensed soup and stir to combine.
Add in the water, milk, and mashed potatoes. Stir until the potatoes are mostly dissolved and the broth looks smooth.
Add the turkey and chopped green beans. Stir.
Bring the soup to a boil and while the soup is heating prep the biscuits by cutting them into 8 pieces each.
Once the soup is boiling, add the biscuits to the pot.
Reduce the heat to low and then cover the pot with a lid.
Cook covered on low heat for 20 minutes. Stir halfway to prevent stuff from sticking at the bottom of the pot.
Remove lid and stir again. remove the soup from the heat.