In a five quart slow cooker, combine dry onion soup mix, cream of mushroom soup & beef broth. Whisk to combine (don't worry if there are any lumps; they will come out as it cooks.
Cut beef into about 1.5 inch cubes (or use pre-cut beef tips). Sprinkle lemon pepper seasoning on beef.
Add meat to crock pot and give it a good stir.
Cover and cook on low for at least 6-8 hours.
Once ready, work on gravy if you'd like it thicker. In a medium pot, melt two tbls butter. Once melted, add in about 3 heaping tbls of flour. Whisk it together until smooth.
Pour in 2 cups of the beef broth mixture into the butter/flour mixture. Whisk until smooth and bring the heat up to high. Once it reaches desired thickness, take off heat and return gravy to crock pot.
Serve over rice, noodles, or whatever strikes your fancy!