Peel and finely dice the onions. Clean spinach, wash well and pluck into small pieces. Wash salmon, dab dry, cut into cubes and sprinkle with some lemon juice. Heat the oil in a pan with a high rim. Sauté shallots in it. Dust with flour and sauté for about 1 minute. Deglaze with vermouth and let it boil down for about 2 minutes.
Add cream and broth and cook over high heat for about 5 minutes. Cook the pasta in boiling salted water for about 10 minutes. Add salmon to the sauce and cook over low heat for about 6 minutes. After about 3 minutes add spinach. Season the sauce with lemon juice, salt, pepper and sugar. Drain the pasta and arrange on plates with the sauce. Garnish with dill tips