The day before you want to make the stew, combine the cubed beef, beer, and smashed garlic in a gallon freezer bag, seal tight, and store in the fridge 12-24 hours to marinate the meat.
The next day, combine the tapioca flour, sea salt, & pepper in a small mixing bowl.
Strain out the meat from the marinade – BUT DON’T THROW OUT THE BEER/MARINADE.
Coat the meat in the arrowroot mixture and sear in a very hot fry pan coated with butter, tallow, or coconut oil. Just sear up the sides - it doesn't have to be cooked all the way through.
Once the beef is done searing, add it to your large slow cooker along with the rest of the ingredients, including the marinade.
Stir to combine and cook on low for 8 hours.
Salt and pepper to taste.
Leftovers can be stored in the fridge, packed in the school lunch thermos or travel crockpot for work, and/or frozen for dinner another time!