Add potatoes to a large pan of water, bring to the boil and cook until tender. 

Dice potatoes, and combine with remaining ingredients (apart from vegetable oil) in bowl. Mix well, being careful not to mash. 

Divide mixture into 12 and shape into small patties. Flatten each slightly.

Heat oil in frying pan until sizzling, add spinach and feta potato cakes in batches and reduce heat slightly. Cook until golden on both sides. Repeat with remaining. 

Drain well on absorbent paper and serve.