Preheat an oven to 160 C / Gas 2 1/2. Whilst waiting for the oven to preheat start preparing your salmon. Firstly chop the spring onions and red chillies finely.
Place each salmon fillet on a seperate sheet of foil. Drizzle one teaspoon of the soy sauce over each fillet. Sprinkle half a teaspoon of the garlic powder over each fillet. Place the red chillies and spring onions in equal amounts across the fillets. Add a teaspoon of butter on top of each fillet.
Wrap up the salmon fillets in the tin foil and place on a baking tray.
Bake in the oven for 25 minutes. After 25 minutes, take out of the oven and place on plate, remove the foil and drizzle the juices over the salmon.