Clean and wash spring onions and cut into fine rings. Heat the fat in a pot and fry the white spring onion rings in it. Dust with flour and sauté briefly while stirring. Pour in the stock while stirring, bring to the boil and simmer for about 3 minutes
Prepare the pasta in boiling salted water according to the instructions on the packet. Cut salmon into strips. Wash tarragon, shake dry and chop except for something to garnish. Add the frozen peas and the remaining spring onions to the sauce and cook for about 3 minutes.
First stir the cream cheese into the sauce, then add salmon and tarragon and heat briefly. Season to taste with salt and pepper. Drain the pasta on a sieve, mix with the sauce and divide into 4 deep plates. Sprinkle with remaining spring onions and garnish with tarragon