Place steak in the slow cooker. Add potatoes and pour in beef stock.
Sprinkle with Lipton onion soup mixture and beef gravy packet.
Top with butter.
Cover and cook on low 7-8 hours or on high 3-4 hours.
Notes
Although we use sirloin steak in this recipe, you can use cube steak, ribeye steak, flat iron steak, etc.
Storage and reheating
Leftovers can be stored in the fridge for up to 4 days in an airtight container. I don't recommend freezing this recipe as steak can become tough and the potatoes mushy when reheated.Reheat - To reheat, simply remove from the fridge and heat in a pot on the stove over medium heat until warmed through.