Cook the spaghetti al dente in plenty of salted water.
In the meantime, peel off the onion and the clove of garlic and dice finely. Put some olive oil in a pan and sauté the onion. Add the garlic and sauté as well. Add the frozen peas and season with pepper. Let simmer briefly over low heat and then pour in the vegetable stock and cream and simmer for 8 minutes over low heat.
Cut the smoked salmon into short strips. Rinse the parsley, shake dry and roughly chop the leaves. Put both in the sauce and season with salt and pepper.
Drain the pasta in the sieve, drain well and mix with the sauce. This works quite well with 2 spoons. Serve immediately.