Preheat oven to has mark 4, grease a round ovenproof dish about 4 cm deep with low fat cooking spray, simmer potatoes for 10 minutes, adding the peas for the last 3 minutes.
Fry the spring onions in low fat cooking spray for 2-3 minutes until softened
Beat the eggs and milk and stir in the potatoes onion and salmon season.
Pour into dish and cook in oven for 35 minutes until just set.