Place the chicken thighs in a saucepan of cold water with the spring onion and ginger. Bring to a boil, reduce heat and simmer 15 minutes or until cooked through. Remove, let cool and shred the chicken.
Meanwhile, in a bowl combine crushed garlic, sesame paste, soy sauce, vinegar, sesame oil, salt and sugar. Mix well.
Bring a saucepan of water to the boil and cook the rice noodles. Drain and rinse with cold water, then toss with chilli oil.
Divide noodles between two bowls. Top with shredded chicken, cucumber, optional pickled mustard greens and drizzle with the sauce. Stir and eat!