Cook the pasta in boiling salted water according to the instructions on the packet. Wash salmon, dab dry and cut into cubes. Peel and finely dice the onion. Heat oil in a frying pan. Fry the salmon in it in portions until golden brown.
Remove and put aside. Deglaze frying fat with cognac, stock and cream. Stir in the crab paste. Bring to the boil and simmer for 5 minutes. Season to taste with salt, pepper and lime juice. Wash the dill, dab dry and pluck flags from the stalks, except some for garnishing.
Chop the dill finely and stir into the sauce. Add salmon and fold in carefully. Arrange noodles and salmon sauce on plates. Garnish with remaining dill.