In a 6 quart slow cooker, mix together the cream of mushroom soup, beef broth, onion soup mix, and A1 steak sauce until well combined.

Add the frozen meatballs and stir to coat them evenly in the sauce. Cover and cook on Low for 6–8 hours or High for 3–5 hours.

If serving with egg noodles, cook the noodles according to package directions while the meatballs finish cooking. Drain well.

Once the meatballs are done, stir in the sour cream until the sauce is smooth and creamy.

Serve the meatballs over the noodles or toss everything together before serving.