Cook the linguine in a large saucepan of boiling, salted water for 8-10 minutes until 'al dente'.
Meanwhile, heat the olive oil in a large frying pan set over a medium heat. Stir-fry the salmon for 4-5 minutes until just cooked, then stir through the courgette.
Remove from the heat and set to one side. Drain the pasta and toss immediately with the courgette and salmon. Stir through the crème fraîche and season to taste with salt, pepper and lemon juice. Stir in the mint leaves just before serving in bowls.