Step 1

Grate potatoes coarsely into a large bowl. Squeeze out excess liquid. Add tuna, egg, parsley and flour, mix well to combine. Season.

Step 2

Heat half the oil in a large frying pan over moderately high heat. For each patty, shape 1/2 cup of tuna mixture into a round. Flatten slightly to make 10cm rounds.

Step 3

Cook, in batches, 3-4 minutes each side, or until golden brown and cooked. Transfer to paper towels to drain. Top up and reheat oil between batches.

Step 4

Whisk yoghurt and garlic in a small bowl until combined. Season.

Step 5

Serve cakes with salad, lemon wedges and yoghurt sauce, if you like.