Quarter potatoes. Place in a pot of lightly salted water and bring to the boil. Cook for 15 minutes, drain really well, then mash with a little butter or oil. Add salt and pepper to taste.
Finely chop onion add a dash of oil to a frypan, and fry until soft.
Prepare yoghurt dip by dicing about 10cm of a cucumber, finely chop about a handful of mint, and toss to combine in thick, greek yoghurt. Add a dash of pepper to taste.
Mix all the ingredients apart from the cornflake coating together. If too sloppy to handle, add more breadcrumbs.
Moisten hands with water, and form into rissoles and coat each one in cornflake crumbs.
Add a dash of oil to the same frypan you fried the onions in, and fry in batches over a medium heat for 3-4 minutes on each side, or until well browned.
Drain on paper towels, and keep warm in the oven while you fry the remaining rissoles.
Serve with salad or cooked vegetables of your choice. Top with mint and cucumber yoghurt.