Prepare Potatoes: Cut the potato into bite-sized pieces and place in a saucepan. Cover with water and season with sea salt. Cook on high heat.
Cook Cod Mixture: In a fry pan, heat olive oil over medium heat. Add chopped onion and garlic, sauté for 3 minutes until translucent. Add chopped cod and cook until just done.
Mash Potatoes: Once potatoes are cooked, drain and rinse under cold water. Transfer to a bowl and mash until semi-mashed.
Combine Mixture: Add the cod mixture, eggs, parsley, salt, and pepper to the mashed potatoes. Mix until well combined.
Fry Fritters: Heat olive oil in the same fry pan over medium heat. Add spoonfuls of the mixture in batches, frying for 4-5 minutes per side until golden.
Serve: Transfer fritters to a plate lined with paper towels to drain excess oil. Serve garnished with lemon wedges.