Wash, peel, dice the potatoes.
Add the diced potatoes to a stock pot and cover with water.
Bring to a boil.
Cook for 5-7 minutes, or until tender.
Drain water. Let potatoes cool.
Open tuna cans, and drain the water from the cans.
Add the cooked potatoes, tuna, egg, onion, breadcrumbs, salt, and pepper to a large container.
Form patties. About 1-inch thick.
Heat oil in a large skillet.
Fry on both sides for 2-3 minutes.
Remove and place the patties on a paper towel to drain any excess oil.
Cover with aluminum foil to keep warm.
Repeat with each of the patty until there are no more left.
Serve and enjoy.