Dice carrots, celery, and onion, and add to a stock pot with a bit of olive oil. Season with salt and pepper and sauté until just softened.
Add chicken stock and stir, bring to a simmer for 10 minutes. Meanwhile, remove the best meat from the rotisserie chicken. I just use my hands and sort of tear it into strips. Add the chicken and a few pieces of lemon peel to the pot and continue cooking the remainder of the 10 minutes, and then turn the heat off. Remove lemon peels.
Prepare your bowls by placing half an avocado, peeled, but still intact, cut side down in the bottom of each bowl. Ladle the soup with all the veggies and meat over the avocado half and top off with chopped cilantro. Serve hot.
