Step 1

Heat a large non-stick frying pan and dry-fry the prosciutto in batches until crisp. Set aside. Add the oil to the pan with the onions and garlic. Cook until the onion and garlic soften and start to turn golden.

Step 2

Boil the spaghetti, following pack instructions. Meanwhile, pile the mushrooms into the pan with the onions and cook, stirring frequently, until they reduce and start to colour. Add the tarragon or thyme and the walnuts, and cook for a few mins more.

Step 3

Drain the spaghetti, reserving a little water. Toss the spaghetti with the garlic mushrooms and parsley and, if the mix looks a little dry, splash in a small amount of the cooking water to moisten it. Slice or tear the crispy prosciutto and toss through before serving.