Cook the noodles following the instructions on the packaging, then drain, run under cold water and set aside.
Crush the sesame seeds in a mortar, then stir in the soy sauce, 1 tablespoon of oil, 1 tablespoon of water and vinegar, to make a creamy dressing, season and set aside.
Heat a pan over medium heat and add in the spinach, cook until wilted. Next add in the cooked noodles and sesame dressing stirring well until heated through.
Heat the remaining oil in a non-stick frying pan over a medium to high heat.
Season the seabass with salt and pepper, then place the fillet in the pan skin-side down. Fry gently for around 3 minutes. Flip the fish over and fry for another 30 seconds, until the fish is just cooked through.
Divide the noodles between 2 plates, place the fish on top and serve immediately.