Put the chicken breast in a pot with the 8 cups of water or stock. Add the bruised lemongrass and kaffir lime leaves. Bring to a gentle simmer, then drop the heat so it barely bubbles. Poach for 15 to 18 minutes, until the chicken is just cooked through. Lift the chicken out and set it aside to cool. Keep the poaching liquid, this is your broth.

While the chicken poaches, make the spice paste. Blend the shallots, garlic, ginger, turmeric, coriander, and macadamia nuts with a splash of water into a rough paste.

Heat the oil in a wide pan over medium heat. Add the spice paste and fry it slowly, stirring often, for 5 to 7 minutes. You want it to darken slightly and smell toasty with no raw onion sharpness left. This step is what gives the broth its depth, so do not rush it.

Scrape the fried paste into the pot of broth. Add the salt and white pepper. Simmer everything together for 10 minutes so the flavors marry. Taste and adjust salt now, the broth should be savory and bright.

Shred the cooled chicken into bite-sized pieces with two forks or your fingers. Soak the rice vermicelli in hot water until soft, about 5 minutes, then drain. Blanch the bean sprouts in boiling water for 30 seconds and drain.

Build each bowl: a nest of noodles, a handful of bean sprouts, a generous pile of shredded chicken, and half a hard boiled egg. Ladle the hot broth over the top, fishing out the lemongrass and lime leaves as you go.

Finish with scallions, fried shallots, a lime wedge, and a spoon of sambal on the side. Squeeze the lime in right before eating.