In a large saucepan over a high heat, boil the ham hock or joint for 90 minutes in enough water to cover the meat. Turn every 30 minutes.
Remove the hock from the water (see tip) and skim off any scum or fat layers, this is now the base for the soup. Add in the carrots and turnip then simmer on a high heat for 10 minutes until tender. Add in the chopped leeks and let them cook for a further 10 minutes.
Make up 1 litre of vegetable stock with the 4 stock cubes in a jug, and add into the soup. Rinse the lentils and stir into the soup, allow these to cook for twenty or so minutes on a medium to high heat until soft and losing their shape.
Add in the potatoes and allow to cook until soft enough to cut with a fork or spoon. Add in the chopped parsley, a sprinkle of garlic granules and a generous helping of black pepper. Cook for ten minutes and it's ready!
Serve with crusty bread of any type, tiger bread is good!
At the beginning of step two you can remove the ham from the soup and allow to cool slightly before removing the meat from the bone and adding back to the soup, discarding the bone.