A great way to cook tri tip is to put in in your slow cooker (Crockpot). Put a layer of peeled, cubed potatoes on the bottom. On top of that put your tri tip. Then sprinkle a package of Lipton Onion Soup Mix on top of the meat. Next, sprinkle 1/2 cup of water on top of the soup mix. Turn the cooker on low and cook for 7 or eight hours.