Check the sauce about halfway through cooking. Depending on your crockpot and the vegetables you added, your teriyaki sauce may be a bit runny. If so, mix together 2 tbsp of water and 1 tbsp of cornstarch, add it to the sauce, and stir. Turn the crockpot to high and cook for another 10 to 15 minutes to thicken. This slow cooker teriyaki steak recipe is one to keep in your arsenal of easy-to-fix meals for busy weeknights. Order your steak online from Chicago Steak Company to have it shipped to your door and ready to go, prepare everything in the morning, set it in the crockpot, and you’ll have dinner waiting for you in the evening.