Prepare the ingredients. Soak the rice noodles in warm water until soft; drain and set aside. Thinly slice the chicken. Prep the garlic, onion, bell pepper, carrot, and Chinese cabbage.
Fry the curry paste. Heat oil in a pot over medium heat. Add the yellow curry paste and stir-fry until fragrant and slightly oily, about 30 seconds.
Add aromatics. Add the garlic and onion. Stir-fry until the onion softens and smells aromatic.
Build the broth. Add water, coconut milk, fish sauce, palm sugar, and light soy sauce. Stir until the sugar dissolves and bring to a gentle simmer.
Cook the chicken. Add the sliced chicken and simmer gently until just cooked through, about 2–3 minutes. Turn off the heat.
Cook the noodles. Bring a pot of water to a boil. Cook the rice noodles until just tender according to the package. Drain well.
Assemble. Divide noodles between bowls. Ladle the hot yellow curry soup over the noodles and top with the prepared vegetables. Serve immediately.