Heat a large skillet over medium-high heat (or slow cooker). Saute beef sirloin tips with onion in the hot skillet until beef is browned, about 5 minutes.

Stir cream of mushroom soup, milk, red wine, and onion soup mix together in a bowl, pour into the skillet, and stir to coat beef in the soup mixture; bring to a simmer, reduce heat to low, place a cover on the skillet, and cook until the beef tips are tender about 2 hours. Reduce heat to the lowest setting and continue cooking until the beef pulls apart easily with a fork, at least 4 hours more.

Bring a large pot of salted water to a boil. Cook egg noodles in the boiling water, stirring occasionally until cooked through but firm to the bite, about 5 minutes. Drain, but don’t rinse.
Ladle beef tips over egg noodles.