Chop the onion and fry in a little oil or butter until translucent, halve the garlic clove and add. Cut the salmon into pieces and fry with them. Put the pasta in boiling, salted water and cook according to the instructions on the package. Mix the crème fraîche with milk, salt, pepper, sugar, chopped basil, sliced spring onions and vegetable stock and then add to the pan.
When the pasta is ready, drain it, toss in a little oil to prevent it from sticking and serve with the sauce.