Pour 1 cup water into slow cooker. If you have broth, by all means give it some extra flavor!
Place cut potatoes, onions, garlic, tomatoes on the bottom. Place roast on top. Cover and cook 6-8 hours, whichever you prefer.
Baste roast after a few hours to get some extra flavor on top!
Cook peas and serve with roast and potatoes.
Save/freeze juices and any extra potatoes/tomatoes for future beef stew!