In a large pot of boiling salted water, add a drizzle of olive oil, cook the spaghetti to your taste – I personally like them just al dente (around 8-10 minutes of cooking), then drain the pasta, reserving about 150 ml of the liquid.

Meanwhile, in a large pan, heat the olive oil. Add the minced garlic and cook over moderately high heat, stirring occasionally, until the garlic is lightly browned, around 1 1/2 minutes.

Add the chopped leeks and cook for a further 4-6 minutes or until the leeks start to soften. Add the clams, lemon juice, saffron and liquid from the pasta. Cover and simmer until the clams open and are just cooked through, 5 to 8 minutes. Discard any clams that don’t open.

Add the spaghetti to the clams still in the pan, season to taste. Toss over a moderate heat just until the spaghetti absorbs some of the juices, about 1 minute.

Transfer the spaghetti and clams to shallow bowls, sprinkle with the chopped parsley and the lemon zest.

Serve immediately.