Just like classic chicken soup, arroz caldo is nourishment, comfort and healing in a bowl.
In a large pot, heat the oil over medium heat then add the onions and celery (if using). Cook for about two minutes, being careful not to burn the onions. Add the ginger and one tablespoon fish sauce. (You can reserve the remaining fish sauce to taste as you cook.) Cook the ginger for one minute, stirring occasionally to keep it from burning.
Add the chicken, rice and broth and bring to a boil. Once boiling, reduce the heat to low or medium low, cover and simmer until the rice is cooked. Be sure to stir the soup occasionally as the rice has a tendency to stick to the bottom of the pot. You don't want any of it to burn. I cook for at least 30 since I like my arroz caldo with rice that's lost its shape, taking on the texture of porridge. This recipe is super flexible. If you like it soupier, simply add more stock (see note). Just season with fish sauce or salt accordingly.
(Optional step) Traditionally, arroz caldo is served with bone-in pieces of chicken but I take the cooked pieces out of the pot, shred them and add the meat back in. This makes it much more convenient for serving.
Ladle the arroz caldo in bowls and garnish with scallions, toasted garlic, a squeeze of lemon juice, a few drops of fish sauce and ground pepper.
In a small pan, heat 1-2 tablespoons of oil over medium heat. Add the chopped (or sliced) garlic and cook for four to five minutes. The garlic should toast and brown gradually so adjust your heat if you see it browning too quickly. Drain and set aside in a bowl. (Tip: Don't toss the oil you cooked the garlic in--it tastes wonderful and would be a great topping for pasta or can be used for a dip or your next cooking project.)