I have eaten bubble and squeak all my life. What else would you do with the vegetables left over from a Sunday lunch, to go with the meat leftovers? Bubble and squeak is one of those dishes that people argue about so I am not claiming that this is the defintive recipe, I am just sharing my family recipe with you. Quantities are difficult because you are basically working with what you have but as a guideline you want to make the same amount of mashed potato as the vegetables you have leftover. I always add some peas too. I think one of the key ingredients is the white pepper - it adds a little heat and a lot of flavour to the end product.
2 handfuls of cooked cabbage/sprouts/beans/broccoli
1 handful of cooked peas
Potatoes to make 2 handfuls of mashed potatoes
Oil or lard
Boil the potatoes for 20 minutes until soft then mash them with a generous sprinking of white pepper. Chop up the vegetables and mix with the potato along with the egg. Season generously with a little salt and lots of white pepper. Heat a large frying pan, add the oil or lard and heat. When nice and hot put the mixture in the pan in four spoonfuls - leave for a couple of minutes then turn over when golden brown. Repeat.
I always have this with leftover roast meat, pickled onions and pickled walnuts. Just a London girl's recipe.