Lightly butter your slow cooker insert, place the vegetables in the bottom. Sprinkle with one packet of onion soup mix.
Place the beef on the vegetables, sprinkle with the second packet of soup mix. Pour in the broth around the outside. Really just takes a cup of broth, gets the steam going.
Cover and cook on Low setting for 8-10 hours. Check at 8 hours for tenderness. If fork tender, remove and serve, if not tender, continue cooking and checking each hour until tender, for local Thai beef, trust me, 9-10 hours and you will be happy with the results.
If you would like to make an Au Jus dipping sauce, say for roast beef sandwiches, remove the beef and vegetables from the slow cooker and add a touch less than 1/4 cup Worcestershire and 1/4 to 1/2 teaspoon garlic powder to the slow cooker juices, mix well and serve in small bowls for dipping.