So does the canned version come complete with the potatoes then?
Yes it does - here is a picture of a can of Hormel Corned Beef Hash:
Ingredients: Beef and Cooked Corned Beef (Cured with Salt, Sugar, Water, Sodium Nitrite), Rehydrated Potatoes, Water, Salt, Flavoring, Sugar, Sodium Nitrate.
Directions: Range Top: Empty contents of can into skillet. Break apart and fry until crispy, turning with spatula. Microwave Oven: Empty contents of can into microwave-safe container; cover loosely with paper towel. Heat 2.5 minutes or until hot, stirring once halfway through heating. Stir before serving. (All microwave ovens vary. Times given are appropriate.)