Cut the mackerel into pieces and mix with the teriyaki sauce in a bowl.
Warm the sesame oil in a saucepan and add the sesame seeds, spring onions, garlic and beans. Heat through gently for 2 minutes.
Add the stock and bring to a gentle simmer. Cover and cook for 5 minutes.
Stir the mackerel, noodles, sugar and lime juice into the pan and cook gently for 2 minutes until the mackerel is cooked and the broth is hot. Serve immediately.