Bring the chicken broth to a gentle boil in a large saucepan. Add the orzo and cook for 8–10 minutes, until just tender. Stir in the shredded chicken and reduce the heat to the lowest setting.

In a medium bowl, whisk the eggs vigorously for 2 minutes until pale and frothy. Add the lemon juice and whisk to combine. The mixture should be uniform and slightly aerated.

Using a ladle, slowly add hot broth from the pot to the egg-lemon bowl, one ladle at a time, whisking constantly after each addition. Add 5–6 ladles total.

Pour the tempered mixture back into the pot in a slow, steady stream while stirring gently.

Stir the soup gently over the lowest heat setting for 3–5 minutes until it thickens slightly and turns a uniform golden color. Do not let it boil. Season with salt and white pepper.

Ladle into warm bowls. Garnish with fresh dill and a lemon slice. Add a small drizzle of olive oil if desired. Serve immediately.