Heat the olive oil in a medium Dutch oven over medium heat. Add the carrots, celery and leeks and cook until the leeks begin to wilt, about 2 minutes. Add the chicken, rice and garlic and stir to coat the rice in the olive oil. Cook to toast the rice lightly, about 1 minute. Add the broth, lemon peel, bay leaves and Parmesan rind, if using. Season with 1 ½ teaspoons salt and several grinds of pepper. Bring to a boil and cook for 2 minutes. Cover the pot tightly and turn off the heat. Let sit for 18 minutes without peeking.
Uncover and discard the lemon peel, bay leaves and Parmesan rind, if added. Stir in the lemon juice, parsley and dill. Season with salt, if needed. Serve the soup, passing grated Parmesan at the table.
