Spray a heavy-based frying pan with cooking spray and heat over a high heat. Add the salmon and cook for about 3–4 minutes on each side until browned. Remove, wrap loosely in foil and leave to rest for 5 minutes.
Cook the noodles in a large saucepan of boiling water for about 5 minutes, or according to the packet instructions, until just tender. Drain well and toss with the sesame oil and seeds.
Meanwhile, combine the soy sauce, orange juice and mirin in a small bowl. Pour into the frying pan and bring to the boil, then reduce the heat and simmer for 1 minute.
Divide the noodles between 4 warmed bowls and serve with the salmon and sauce and steamed sugar snap peas on the side.