Place a large pot over medium heat and add the olive oil. Sauté the diced onions for about five minutes until translucent. Add minced garlic and cook for another minute.

Pour the chicken broth into the pot and bring to a gentle boil. Add the orzo pasta and reduce heat to a simmer, cooking according to package instructions.

In a medium bowl, whisk the eggs until frothy. Slowly whisk in the lemon juice and zest.

Ladle out about a cup of hot broth and drizzle it into the egg mixture while whisking constantly to temper the eggs.

Pour the tempered egg mixture back into the pot, stirring continuously over low heat for about three minutes until the soup thickens slightly.

Add the shredded chicken and fresh dill, season with salt and pepper, and remove from heat.

Let the soup cool at room temperature for about thirty minutes, then refrigerate for at least two hours before serving.