Slow Cooker Hamburger Stroganoff is total comfort food. Ground beef and mushrooms simmer away all day in a creamy sauce, and are then served over egg noodles for a hearty wintertime meal.
Season beef with salt and pepper. Transfer to a large skillet set over medium heat, and sauté beef, breaking up as it cooks. When almost browned, add diced onion. Cook for 4-5 minutes until onions are translucent. Add tomato paste, stirring until mixed thoroughly. Transfer beef mixture to the crock of a slow cooker.
Top beef with mushrooms, thyme and Worstershire sauce.
In a 4-cup measuring cup or bowl, combine water, sour cream, flour, bouillon and paprika. Whisk together until combined. Pour over top of beef and mushrooms.
Cook on low for 6 hours.
Serve hot, over egg noodles.