Melt the ham fat in the pressure cooker for a few minutes using saute function for electric cooker or medium high heat for stove top cookers.
Add vegetables and cook for 3-5 minutes until vegetables begin to soften.
Add split peas, stock, bay leaves and ham. Stir to loosen any browned bits on the bottom of the pan.
Secure lid and cook on high pressure for 20 minutes. Let sit 5 minutes then release remaining pressure.
Remove bay leaves. Mash the soup with a potato masher or large spoon.
Thin to desired consistency with water or additional stock if needed. Season to taste with salt and pepper. Serve.
Notes
If you have a ham bone, you can add that and 6 cups of water instead of the ham and stock. After cooking, shred any ham off of the bone and add to the soup.