Wash the asparagus and cut off the ends generously or peel the lower third. Cut the asparagus into bite-sized pieces and cook them for about 5 minutes in just under 1/2 l boiling, lightly salted water with 1/2 tsp. sugar
Peel and finely chop the onion. Dice the gorgonzola. Drain the asparagus, catch the stock
Heat the fat in a saucepan. Sauté onion in it until transparent. Sprinkle with flour and sauté briefly. Add asparagus stock and cream while stirring. Let the sauce simmer for about 5 minutes
Cook the pasta in plenty of boiling salted water for 8-10 minutes until al dente. Add the cheese to the sauce and let it melt while stirring
Season the sauce and heat the asparagus in it. Drain the pasta and serve with sauce and chervil