Add the beef stew meat to the slow cooker.
Sprinkle over the gravy mix and seasonings. Add the tomato paste, Dijon mustard, and garlic.
Add the shallots and mushrooms, pour over the water. Stir together, try to get the tomato paste and Dijon mustard to blend into the gravy.
Place the lid on the slow cooker and cook on LOW for 5-6 hours.
When the cooking time is up, stir in the sour cream and serve!
