Cook your pasta as per the packet instructions and reserve half a cup of the cooking water

Pat the prawns dry and toss with half the lemon zest, the salt, and the pepper

In a large frying pan over a medium-high heat, melt the butter until the foaming subsides

Add the shallot, garlic, and chilli flakes and sauté until the onions are soft

Remove and set aside without discarding the butter

Cook the prawn heads until well coloured and remove

Deglaze the pan with the stock and reduce by half

Return the onion mix to the pan with the prawn tails and cook for 90 seconds

Turn the prawns and add the wine and the lemon juice

Add the mascarpone and bring to the boil

Remove the prawns from the pan to ensure they don’t overcook

Add the pasta and toss well to coat with the sauce

If the sauce needs thinning out, add some or all of the reserved pasta water (a tablespoon at a time)

Adjust the seasoning, add the rest of the lemon zest and the prawns and serve straight away