Soak the rice in plenty of water for about 30 minutes.
Heat olive oil in a Dutch Oven or a large pot over medium heat and add the diced onion and celery. Saute for about 5 minutes, until onions and celery are tender.
Add 4 cups (1 litre) chicken stock, soaked and washed rice, bay leaves, salt, and freshly ground black pepper. Bring the pot to a boil.
Reduce the heat and let it simmer for 20-25 minutes until the rice is tender and cooked through.
Stir in the shredded chicken, bring it back to a gentle simmer, and remove the pot from the heat.
Place the 2 cups (500 ml) chicken stock in a small pot and bring it to a gentle simmer. Remove from the heat.
In a medium bowl, whisk the eggs and lemon juice.
Slowly add a ladleful of the hot stock to the egg-lemon mixture while whisking continuously. The mixture will look frothy at this stage. This step is crucial to temper the eggs and prevent curdling.
Slowly pour the egg-lemon mixture into the soup. The soup will thicken at this stage. Add chopped dill and give it a good stir.
Check the seasoning and add extra salt pepper or lemon juice if necessary. Serve hot, and garnish with extra dill and lemon slices if you prefer.