Clean and wash the broccoli and cut it into florets. Peel and finely chop the broccoli stems. Blanch the florets and stems in boiling salted water for about 2 minutes and drain. Peel and chop the onion.
For the noodles, boil 3-4 l salted water (approx. 1 teaspoon salt per litre). For the pesto, chop the pistachios coarsely. Peel and chop the garlic. Grate half of the Parmesan cheese. Good 1⁄3 Finely puree broccoli, pistachios, garlic, grated Parmesan cheese, crème fraîche, mustard and 100 ml oil with a hand blender.
Season pesto with salt and pepper.
Cook the pasta in boiling salted water according to the instructions on the packet. Heat 1 tablespoon of oil in a frying pan. Press the sausage from the skin directly into the pan. Slightly chop with a spatula and fry for about 10 minutes, turning occasionally.
After about 5 minutes fry the onion and the rest of the broccoli.
Drain the pasta and put it back into the pot. Add the pesto and broccoli together with the sausage. Mix everything and serve. Slice the rest of the Parmesan cheese over it.