Bring 2 liters of water to a boil and salt it generously, about 1 tbsp per liter. Cook the pasta al dente according to the package.
Finely chop the celery and cut the cold smoked salmon into bite-sized pieces. Heat the olive oil in a frying pan over medium heat and sauté the celery for a couple of minutes, until slightly softened. Squeeze in the lemon juice and add the cream. Season with white pepper.
Add 2 dl of the pasta cooking water to the pan. Bring the sauce to a boil and take the pan off the heat.
Drain the cooked pasta. Stir in the cream sauce, the cold smoked salmon and the chopped dill. Don't heat it any further, so the salmon stays juicy.
Serve right away, garnished with dill sprigs.
Notes
Add the salmon at the very end.
If the sauce feels thick, add a splash of pasta water.
Grate in some lemon zest too for an extra fresh flavor.