Blend 1 teaspoon of coriander seeds, 1 teaspoon of cumin seeds, 4 shallots, 3 garlic cloves, 1 tablespoon of ground turmeric, 1 piece of galangal, 1 piece of ginger, and 1 tablespoon of lime juice to a fine paste, adding water if needed.
Heat 2 tablespoons of cooking oil in a pot and fry the paste until aromatic. Add 400ml of chicken broth, 400ml of coconut milk, 1 cup of water, and 1 lemongrass stalk.
Add 1 skinless, boneless chicken breast, cut into cubes, and simmer over low heat for 30 minutes. Season with salt to taste.
Soak ½ package of rice noodles in warm water until soft. Blanch the noodles, then 2 cups of bean sprouts, in boiling water. Drain and divide between bowls.
Ladle over the hot soup and chicken. Top with 2 hard-boiled eggs, cut into wedges, and 1 sliced scallion.
