My grandmother made huge batches of this soup and doled it out to her kids and grandkids in ziptop freezer bags. After she died my mother kept a bag of her split pea soup in the freezer for 10 years. She couldn't bear to eat it.
Chop the onions, celery and carrots. Aim for 1/2-inch pieces, but don't get all OCD about it. You want them all roughly the same size, but a little bigger or smaller won't make a difference at all.
Heat the oil in a large pot and brown the ribs on all sides. Remove the ribs to a plate, then add the chopped vegetables to the fat in the pot. Stir a minute or two until everything is coated in fat and starting to soften.
Put the meat back in the pot, then add the split peas, pearl barley and dried dill. Add enough water to cover it all and bring the pot to a boil. Turn the heat down to low, cover the pot, and simmer the soup at least 2 hours, until it is thickened and the meat is tender.
Shred the meat with two forks (or your fingers if you've let the soup cool for a while). The bones will have slipped out of the meat, so fish them out from the bottom of the pot with a spoon. Season with salt and pepper - you will need much more salt than seems reasonable, but keep salting until it tastes right to you. Serve hot for a hearty one-pot lunch or dinner.