Place the split peas, beef shank, and pork shoulder chop in a large soup pot and cover with water. Bring to a boil.

Reduce the heat and simmer gently for an hour or an hour and a half. Remove the meat from the pot and skim the soup with a skimmer.

Add the potatoes, white beans, leeks, carrots, and celeriac to the soup. Bring it back to a boil. Reduce the heat to low, and let the soup simmer for about two hours, until the split peas are completely soft.

If necessary, skim the foam off the soup occasionally while it's cooking.

Remove the meat from the beef shank and shoulder chop, then cut or pull it into small pieces. Add the meat to the soup along with the celery leaves and smoked sausage.

Add a little extra water (or broth) if the soup becomes too thick. Season the pea soup with freshly ground black pepper and salt to taste. Enjoy!