For a richer flavor, sear the beef cubes in a skillet before adding them to the slow cooker. Adjust the amount of teriyaki sauce to your preference. Taste the sauce during the last hour of cooking and add more if desired. If you don't have pot roast seasoning, use a combination of onion powder, garlic powder, smoked paprika, and dried thyme. Feel free to add other vegetables to the slow cooker, such as sliced carrots, mushrooms, or bell peppers. Store leftovers in an airtight container in the refrigerator for up to 3 days.