In a small bowl add the cold water and corn starch, whisk with a fork until smooth. Add to the slow cooker along with the broth. Mix the broth with the cornstarch slurry.
Add meatballs to the bottom of the slow cooker.
Top with cream of mushroom soup, brown gravy mix, Worcestershire sauce, dried parsley, garlic powder, and onion powder. Stir well to mix all ingredients. It's ok if the cream of mushrooms doesn't dissolve, it will melt with the cooking time.
Place the lid on the slow cooker and cook on high for 3 hours or low for 5 hours. Stir occasionally towards the end of the cooking time.
When cooking time is complete, add the sour cream and stir. Serve the meatballs and gravy over large egg noodles or rice.
How to store?Meatballs will last in the fridge for about four days or in the freezer for three months.How to reheat?The quickest way to reheat a small serving of these meatballs is in the microwave. You can also reheat it on the stovetop in a saucepan.Can I use a different noodle?You can use different noodles, but it will change the flavor. Egg noodles have a taste and shape that is traditional with egg noodles. You can also skip the noodles and use rice or mashed potatoes with them.