Bring a pan of salted water to the boil and put a steamer (or colander) over the water.
Steam the beans, asparagus and peas until just tender, then set aside.
Boil the pasta following pack instructions.
Meanwhile, fry the leeks gently in the oil and butter for 5 mins or until soft. Add the fromage frais to the leeks and very gently warm through, stirring constantly to ensure it doesn’t split. Add the herbs and steamed vegetables with a splash of pasta water to loosen.
Drain the pasta and stir into the sauce.
Adjust the seasoning, then serve scattered with the cheese and drizzled with a little extra olive oil.
Source: bbcgoodfood.com