Bring a pan of salted water to the boil and cook the pasta for 2 mins less than pack instructions.
Meanwhile, heat the oil in a large frying pan over a medium heat. Add the garlic and fry for 2-3 mins until softened but not coloured. Stir in the crème fraîche, lemon juice, Parmesan and 2 ladles of pasta cooking water. Allow to bubble gently for 1 min.
Drain the tagliatelle and mix into the sauce in the frying pan. Cook for a further 2 mins or until reduced to a creamy sauce that coats the pasta.
Stir through the smoked salmon and chives, season with black pepper, then divide between 4 bowls. Garnish with the lemon zest and top with a handful of rocket.
