Melt 1 tbsp butter in pan over medium heat then add mushrooms and cook for 5 minutes.
Add pan drippings and cook for a minute.
Add flour and mix, cooking for 2 minutes.
Whisk in chicken stock, fresh herbs, worcestershire, salt, and pepper. Bring to a simmer and cook for 5-7 minutes.
Turn off heat and add remaining butter and stir into gravy.