Place the potatoes in a saucepan and cover with cold water. Bring to the boil. Reduce the heat, cover and simmer for 20 minutes until just tender.
While the potatoes are cooking, strip the kale leaves from the stems and discard the stems. Wash well then thickly shred. Add to the potatoes for the last 5 minutes of cooking.
Drain well, then mash.
Heat 1 tbsp of oil in a frying pan and add the onions and bacon, if using. Cook over a low heat for 5 minutes until softened and beginning to colour. Add to the drained potatoes and kale.
Leave until cool enough to handle. Season well and add the beaten egg. Beat to combine.
Shape into 8 cakes with your hands. Dust with flour.
Heat the remaining oil in a frying and fry in two batches for 4-5 minutes each side until golden brown and piping hot.
After shaping, the cakes can be chilled until required. Keep in the refrigerator for up to 2 days.They also freeze well. defrost before reheating.Nutrition information is approximate and is meant as a guideline only. (It does not include seasoning with salt and pepper.)