Melt a spoonful of ham fat in a big soup pot on medium low. (Note: ham fat is the dripping from a baked ham, saved in a container in the fridge. Substitute bacon fat or olive oil.)
Chop a big onion, three stalks of celery and several carrots and saute in the hot fat. Add fresh chopped herbs such as sage and thyme. Cook, stirring now and then, until it smells fabulous and the vegetables are softening. Season with salt and pepper. If the fat is absorbed, add some olive oil to keep things from sticking to the pot.
Add a few cups of split green peas. (I think I used about 3 cups, but I didn't measure exactly.) Stir well so the peas are coated with fat/oil. Cook until the peas start to stick to the bottom of the pot. Pour on water to cover completely, and a bit more.
Add a ham hock and two bay leaves. Bring to a boil, then cover and turn down the heat, simmering for several hours until the peas turn almost to mush. You'll need to add more water along the way, so keep your eye on it.
Remove the ham hock and bay leaves. When cool, remove the meat from the bone. Chop the meat and return it to the pot.
Taste the soup and add more salt and pepper as needed. Ladle into bowls, top with grated cheese and eat!