1Place the onion, shallots and ginger cut-side down in a dry pan over medium-high heat and cook until browned and fragrant.
2Add the bones, aromatics, water and a teaspoon of salt to a pot, bring to a boil, skim away foam, and simmer.
3Add the chicken breast to the pot and poach until it reaches 165°F (74°C).
4Remove the chicken, let it rest, then shred it.
5Strain the broth and return to the pot; season with fish sauce, chicken bouillon, sugar, and salt to taste.
6Boil the miến noodles in water until tender, then drain.
7Assemble the bowl by adding noodles and shredded chicken, then ladle over the hot broth and garnish with green onions, cilantro, rau răm, fried shallots, and black pepper.