1.5 kg lamb shoulder
1 kg lamb shanks
1 large onion
2 stalks celery (cut in half)
2 large carrots (cut in half)
5 whole black peppercorns
1 stick of butter
1/2 cup olive oil
4 bunches green onions, minced (trim only ends of green part)
1 bunch fresh dill, minced (about a cup)
1/2 bunch fresh parsley, chopped (about 1/2 cup)
3 tbsp cornstarch (rounded)
Juice of 3-4 lemons
Salt and freshly ground black pepper to taste
1. Wash and rinse the lamb bones and trim them of any excess fat.
2. In a large soup or stock pot, add the lamb shoulder and lamb shanks. Add water and cover the bones and meat by about 7 cm. Add the onion, celery, carrots and black peppercorns to the water.
3. Bring to a boil, partially cover, and simmer over medium heat for 2 – 3 hours. Skim the surface with a slotted spoon to remove any foam and impurities that may rise to the top.
4. Remove the meat and bones to a large platter and set aside. Discard the vegetables. Place a fine mesh strainer over another pot or large bowl and strain the remaining broth. Discard peppercorns. Rinse the original soup pot and return to the stove.
5. You should have around 12 cups of broth to make the soup. If you don’t have quite that much you can add some water or chicken broth to supplement.
6. Remove the meat from the bones and chop into small pieces. Discard any fat and gristle.
7. In the soup pot, melt the butter. Add the olive oil and heat over medium high heat. Add the green onions, dill, and parsley and saute until tender, about 10 minutes. Add the chopped lamb meat to the green onions and continue to saute until the meat is slightly browned. You may need to drizzle a little more olive oil if it seems too dry.
8. Carefully add the strained broth back to the pot and return to a boil. Simmer another 20 – 30 minutes.
9. Add the cornstarch to a measuring cup or bowl and dissolve with hot broth. Add the dissolved cornstarch back to the simmering pot.
Note: The lamb broth can be made a day ahead. You can chill the broth overnight in order to de-fat it easily before proceeding with the avgolemono. This is optional. You can also remove any excess fat by skimming the oil off of the top of the surface with a spoon.
Make the avgolemono:
Beat the eggs in a large bowl until very frothy and light. While continuing to beat, slowly drizzle in the lemon juice.
Slowly incorporate about 2 cups of the simmering broth to the egg-lemon mixture to temper the eggs and prevent them from curdling when added to the soup pot.
Carefully add the tempered egg-lemon mixture back to the soup pot and heat over very low heat for a few minutes. Be careful not to let it boil or the soup will break.
Adjust salt and pepper to taste and enjoy.