Iceberg Ham and lettuce Soup

I first started out to make a ham and bean soup.
Finding out there wasn't a bean in the house.
I raided the refrigerator,
found lettuce and this recipe was born.

Ingredients:
3 cups chicken stock
1/4 cup cooked leftover ham, cubed
1 onion, peeled and sliced
1 head iceberg lettuce, chopped
1 egg, lightly beaten
1 tablespoon unsalted butter
black pepper to taste

Directions:
In a soup pot bring broth to a boil.
Add ham and onion, lower heat to simmer for 3 minutes.
Raise heat to a boil and add lettuce.
when lettuce starts to wilt, add egg, butter, pepper
and lower heat to simmer, while stirring until egg coagulates.
serve immediately.