Pick peas over, discarding malformed peas and any small stones. Rinse and put in a large bowl. Add water to about 2 to 3 inches above the peas. Let stand at room temperature overnight. 

Drain the peas and rinse. 

In a large pot or Dutch oven, cook the pork belly or salt pork with the onion, celery, and carrot until onion is translucent and the pork is browned. Add the drained peas, chicken broth, and enough water to cover the peas. Add the ham, crushed red pepper, and black pepper. Cover and simmer for about 1 hour, or until tender. If using pork belly, remove and shred the meat, discarding the fat. 

Add the meat back to the peas and add salt, to taste. 

Serve with rice and cornbread.