I bought a large ham hock in Tesco, called a pork side leg. Looks like a hock, and it is pre-cut through the bone in 4 places. The tape measure is in inches, this thing is huge, and only 120 Baht, weight is about 1 1/2 kilos. I only used about half, the right 3 sections for the soup, so the cost was only 60 Baht, my wife used the left 2 sections for a Thai soup.
Add the hock to the slow cooker pot first.
Then add the rinsed split peas around the hock.
Add your diced carrot on top.
On top of the carrot, add the onion, bell pepper if using that, garlic, celery, spices and bay leaves.
Pour in your chicken stock, place the lid on and cook on High setting until split peas are creamy and pureed. Check the peas at 4 hours, when the peas are cooked, they will be soft and will puree on their own by simply stirring them, if not soft, check again at 5 hours, etc.
At the 4 hour mark, use a meat thermometer to check the temp in the hock, if it is cooked through, remove the hock to a plate, remove the skin and fat then roughly chop the meat and return the meat to the pot and stir that in. This cut of meat has a lot of fat, so you will need to skim that off the surface of the soup from about the 4 hour mark onwards.
When the peas have pureed for the most part and the pork is cook, chopped and added back, turn the slow cooker down to Warm setting, discard bay leaves and you are ready to serve.