Fettuccine primavera (pasta with spring vegetables)

For ➍
½ small yellow onion
1 large carrot
1 medium celery stalk
4 tbs butter
500 g asparagus
¾ red bell pepper
1½ medium zucchini
20 cl heavy cream
4-5 sprigs flat-leaf Italian parsley
salt & freshly ground black pepper
75 g freshly grated Parmigiano-Reggiano
250 g dried egg fettuccine or tagliatelle

Peel and finely chop the onion. Peel the carrot and cut into 1 cm dice. Wash the celery, trim the top and bottom, and peel the back to remove the tough strings. Cut it into 0.5 cm dice.
Put the butter in a 25 cm skillet and place over medium-high heat. Once the butter begins to melt, add the onion, carrot, and celery and sauté until the vegetables begin to brown, about 5 m.
While the vegetables are sautéing, fill a 25 cm skillet with water and place over high heat. Cut off the white, woody bottom part of the asparagus spears, then peel the remaining bottom third. Add 1 ts  to the boiling water, then gently slide in the asparagus. Cook for 5 to 6 m or until the asparagus is tender, then lift them out and set aside. [Read tip].
Fill a pot for the pasta with about 2 l of water, place over high heat, and bring to a boil.
Wash the zucchini, trim the ends, and cut into 1 cm dice. Peel the pepper, core it and remove the seeds. Cut away any white pith inside the pepper and cut into 2 cm squares.
When the onion, carrot, and celery are ready, add the zucchini and peppers. Season generously with salt and pepper and continue sautéing until the zucchini and peppers are quite tender and lightly browned, about 15 m.
While the zucchini and peppers are cooking, finely chop enough parsley to measure 1½ tablespoons. Cut the cooked asparagus into pieces about 2-2.5 cm long. When the zucchini and peppers are ready, add the asparagus and sauté for about another m. Add the cream and parsley and continue cooking until the cream has thickened and reduced by almost half.
While the cream is reducing, cook the pasta. Add about 2 tbs salt to the boiling pasta water, add the fettuccine, and stir until all the strands are submerged. Cook until al dente.

When the pasta is done, drain it well, toss with the sauce and the freshly grated Parmigiano, and serve at once.