Start by peeling and chopping the potatoes into chunks. Place them in a pot of boiling water and cook until fork-tender, about 15-20 minutes. Once cooked, drain and mash them in a mixing bowl until smooth.
To the mashed potatoes, add the drained canned tuna, chopped parsley, lemon zest, rinsed capers, sea salt, black pepper, and breadcrumbs. Drizzle in the extra virgin olive oil. Mix everything together until well combined.
Using your hands, take small portions of the mixture and roll them into balls, about the size of a golf ball. Place the meatballs on a baking sheet lined with parchment paper, spacing them evenly.
Preheat your oven to 180°C (350°F). Bake the meatballs for 20-25 minutes, or until they are golden brown and heated through. You can flip them halfway through baking for even browning.
Once baked, remove the meatballs from the oven and let them cool for a few minutes. These tuna meatballs can be served warm with a side of your choice, drizzled with a sauce, or even enjoyed cold as a snack!
