Boil the potatoes for 12-15 minutes until tender.

Drain the potatoes and return to the pan over low heat for 1-2 minutes to dry out.

Add the butter and mash the potatoes well.

Boil the Brussels sprouts for 3-5 minutes until just tender.

Drain the Brussels sprouts and cool quickly under cold running water.

Shake the Brussels sprouts dry, then shred them finely.

Mix the shredded sprouts with the mashed potatoes and season to taste.

Let the mixture cool until easy to handle.

Shape the mixture into 8 round cakes.

Tip the flour onto a plate and coat the cakes, tapping off any excess.

Heat a 5mm depth of oil in a large frying pan.

Shallow-fry the cakes in 2 batches for 2 minutes each side, turning carefully.

Drain the fried cakes on kitchen paper and transfer them to a baking sheet lined with greaseproof paper.

Cool, cover, and chill or freeze the cakes.

Heat oven to 190C/fan 170C/gas 5.

Reheat the cakes for 15 minutes until hot and crisp on the outside.