Wash the yellow split peas carefully. Cover them with chicken broth, add the chopped onions, salt pork, bay leaf and herbs and bring to a boil. Lower the heat and simmer, partially covered, for 1 to1 1/4 hours or until the peas are tender but have not fallen apart.
Remove salt pork from the soup; discard the bay leaf and season soup to taste with salt and pepper. Cut the salt pork into 1/4 inch slices. Place a few slices of pork in individual serving bowls, ladle soup over the pork and serve with good rye bread.
VARIATIONS Add a chopped carrot and stalk of celery to the mixture; after you remove the salt pork, puree the soup and thin with more stock if too thick.
Or simmer soup without salt pork; saute kielbasa until crisp, slice thinly and serve in soup.