Heat avocado oil in a heavy-bottomed pot over medium heat and sauté the diced onion, minced ginger, and garlic until they are soft and fragrant.
Add the cubed chicken breast to the pot and cook for 3-4 minutes until the exterior is lightly browned.
Stir in the jasmine rice and fish sauce, tossing the grains for one minute to toast them slightly and absorb the aromatics.
Pour in the chicken broth and bring the mixture to a rolling boil.
Reduce the heat to low, cover the pot, and simmer for 20 minutes, stirring occasionally to ensure the rice doesn't stick to the bottom.
While the porridge simmers, place the egg in a small pot of boiling water for 7 minutes, then immediately transfer to an ice bath before peeling and halving.
Check the porridge consistency; if it is too thick, add a splash of water or more broth until it reaches a velvety texture.
Ladle the hot arroz caldo into a bowl, season with black pepper, and top with the jammy egg halves, sliced scallions, and crispy fried garlic bits.