Boil the pasta ... al dente or not ... be inspired by the instructions on the box ... I like it softer so I always leave them for a minute or two more then cover them and let them swell.
I simmered the green onion and the asparagus in a little olive oil (2-3 minutes) over a moderate heat for about 5 minutes.
Skinless and boned salmon, cut into small pieces, I put it on the grill, it is done very quickly and I put it aside.
I then put in a deep frying pan, the salmon with onion, asparagus, capers and sour cream. We match the taste of salt and pepper. I left it on low heat for another five minutes then I mixed the pasta (still hot) drained well with the feta and the rest of the composition.
Place on a plate and decorate with lemon.
Very very good!