In a large pan, place 1 T of canola oil. While pan is heating up, season beef well with 1 t Cajun seasoning, 1 t cumin, salt and pepper. Add seasoned meat to hot pan and brown on one side until meat is deep brown. Flip meat and brown well on the other side, remove from pan.
Add 1.5 cups of onion to the beef pan and cook until onions turn clear, about 2 minutes. Add 1 T chopped garlic to the pan and cook an additional 30 seconds. Add stock and 2 cups of water to pan, move spoon around until flavor comes off of the bottom of the pan. Place meat in crockpot, pour liquid over it and cook on low until tender, at least 4 hours.