Turn slow cooker on LOW.
Place chopped onion in the bottom of the slow cooker.
Add 2 cups hot water mixed with ¼ cup beef soup base.
Sprinkle Montreal Steak seasoning on both sides of the roast.
Place roast into the slow cooker.
Sprinkle ½ tablespoon crushed red pepper on top.
Add carrots and potatoes.
Sprinkle 2 tablespoons seasoning salt over roast and vegetables.
Pour ½ cup Teriyaki sauce evenly on top.
Cook on LOW for 7 hours.