Step 1

Place potatoes in a small saucepan with enough cold water to cover. Bring to the boil; cook for 25 minutes or until tender. Drain. Return to pan; coarsely mash with a fork.

Step 2

Meanwhile, make harissa yoghurt. Combine ingredients in a small bowl; season.

Step 3

Place grated zucchini in a clean tea towel; squeeze over sink to remove excess moisture. Combine zucchini, chilli, lemon rind, green onion, mashed potatoes and rice flour in a large bowl; season. Shape ¼ cup measures of zucchini mixture into ovals to make 12 in total.

Step 4

Heat 2cm of oil in a large frying pan over high heat. Shallow-fry koftas, in batches, for 3 minutes each side, or until golden and crisp. Remove with a slotted spoon; drain on paper towel.

Step 5

Serve koftas with harissa yoghurt and lemon wedges. Sprinkle with salt flakes, if you like.