In a large pot, combine meatballs, broth, and mushrooms. Bring to boiling; reduce heat. Cover and simmer about 15 minutes or until meatballs are heated through.
In a small bowl, stir together sour cream and flour.
Whisk in milk and mustard.
Stir sour cream mixture into meatballs.
Cook and stir until thickened and bubbly, then cook and stir for 1 minute more.
Serve over hot cooked egg noodles.
Notes
You can purchase frozen meatballs (I’m partial to the Costco brand) or use our bulk meatball recipe.If you are a big fan of fresh mushrooms like I am, you can sauté 8 oz. sliced fresh mushrooms instead of canned for better texture and richer flavor.