About 30–40 minutes before serving, stir the uncooked wide egg noodles directly into the hot beef and gravy mixture, pressing them down so they are mostly submerged. If the mixture seems extremely thick and the noodles are not coated, you can splash in 1/4–1/2 cup water to help them soften, but keep it minimal so the gravy stays rich.
Cover and cook on HIGH for 20–30 minutes, stirring once halfway through, until the noodles are tender but not mushy and have absorbed some of the savory brown gravy. The dish should look glossy, with wavy noodles coated and tangled with crumbled beef in a dark oniony sauce.
Taste and adjust seasoning if needed—depending on the brand of soup and onion mix, you may not need extra salt. Serve hot straight from the slow cooker.
