Place potato into a small pot and cover with salted water. Bring to a boil over high heat, then reduce heat to medium-low, cover, and some until tender, about 20 minutes

Drain and allow top steam dry for a minute or two, then mash the potato with a potato masher or fork in a large bowl

Mux the tinsa, egg, onion, Dijon mustard, breadcrumbs, garlic powder, Italian seasoning, cayenne pepper, salt and pepper into the mashed potato until well-blended.

Devide the tuna mixture into 8 equal portions and shape into patties.

Heat olive oil in a skillet over medium heat.

Pan fry the tuna patties until browned and crisp, about 3 minutes on each side.