Put the peas in a large bowl and pour over 550 millilitres of water and leave overnight. Drain the peas and rinse well in cold water.
Put the peas in a saucepan with the beef stock and bring to a simmer. Cook for 10 minutes then turn off the heat.
Peel the potatoes, swede and carrots and cut into cubes of about 1 centimetre.
Put the carrot, swede and potato in the bottom of the slow cooker.
Finely chop the onion.
Heat the oil over a medium heat in the frying pan. Add the onion and cook for 3 - 5 minutes until softened.
Transfer to the slow cooker with a slotted spoon.
Cut the meat into bite sized pieces.
Sear the meat on all sides. You may need to add a little more oil. When all the meat has been seared return it to the pan.
Sprinkle over the flour and stir with a wooden spoon so that it coats the meat.
Add the stock, thyme and pepper to the pan and bring to a simmer.
Transfer to the slow cooker.
Cook on low for 10 hours or high for 6 - 8 hours.
Check the seasoning before serving.
Scatter over some chopped parsley if liked and grab a spoon.