1. Both the potato and cabbage should be cooked and allowed to go cold.
2. In a large clean bowl mix them together.
3. Check the seasoning, but remember they should already have been seasoned when cooked earlier.
4. Add the egg yolk and mix well.
5. Heat a little oil in a heavy-based frying pan.
6. When hot, add the bubble and squeak mixture and, using a fish slice or palette knife, flatten out the mixture to cover the base of the pan.
7. Allow to fry until the bottom of the mixture becomes brown and crispy.
8. Turn over and do the same again.
9. When it is brown and crispy on both sides, remove the bubble and squeak from the pan into a warmed serving dish or on warmed plates.
10. Serve with garnish as desired.