Wash the sugar snap peas and cut into pieces. Dice gorgonzola. Peel and finely chop the onion. Melt the fat in a pot and sauté the onion. Deglaze with broth, bring to the boil. Add mascarpone and stir until smooth.
Bring to the boil again and add gorgonzola. Season with salt, pepper and nutmeg. Melt the cheese in the sauce and let the sauce boil down at low heat for about 10 minutes. In the meantime heat oil in a pan and fry medallions for 6 minutes on each side.
Cook the pasta in boiling salted water for 8 minutes. Cook sugar snap peas in boiling salted water for 2-3 minutes. Drain sugar snap peas and noodles and let them evaporate. Season medallions with salt and pepper.
Arrange sugar snaps, noodles, medallions and sauce on plates. Decorate with chervil.