Heat 1 tablespoon of vegetable oil in a large pot over medium heat. Add the onions and ginger, and char for about 2 minutes.

Pour in 2 liters of water, chicken thighs, coriander stalks, star anise pods, cinnamon stick, cloves, fennel seeds, and coriander seeds. Add fish sauce, sugar, and salt, then bring to a gentle simmer.

Maintain a gentle simmer for about 1.5 hours, uncovered, skimming off any scum that rises to the surface.

Carefully remove the chicken thighs and strain the broth into another pot, seasoning with salt to taste.

Shred the chicken meat into bite-sized pieces, discarding bones and skin.

Cook the dried rice noodles in boiling water according to package instructions, about 5-7 minutes, then drain and rinse with cold water.

Place cooked noodles in bowls, top with shredded chicken, and ladle hot broth over.

Serve with bean sprouts, sliced green onions, Thai basil, and lime wedges on the side.