Place rinsed lentils in your slow cooker. Mix in vegetable. Add 6 cups of broth and give a quick stir.
Cover and cook on HIGH for 2-3 hours or on LOW for 4-6 hours. Actually cooking time depends on your individual slow cooker.
Drain if necessary.
Stir in barbecue sauce and continue heating for about 30 minutes.
Enjoy or let cool and store in fridge for up to 5 days.