Chop the onions, peel and dice the carrots, peel and cube the sweet potato, and dice the celery so that everything is ready to toss into the bag.
Dump the beef stew meat into a large resealable bag before adding the other ingredients. Remove the excess air from the bag, seal, and freeze.
On the day of cooking, take the meal out of the freezer to thaw.
Cook in the slow cooker for 5-7 hours on low.
You can serve this slow cooker beef stew with buns or on its own.