2: Remove all the shells, place the cockles in a bowl, and reserve a small glass of their cooking juices.
3: Cook the pasta for 3 minutes less than scheduled (it will cook again in the pan), then drain.
4: In a large frying pan over high heat, pour in 4 tablespoons olive oil and when hot, add the parsley stems (set the leaves aside). Cook for 1 or 2 minutes, stirring occasionally, as the oil will take on the taste of the parsley.
5: Pour in the spaghetti, stir for 1 minute, then remove and discard the parsley stems.
6: Pour in 250 g liquid cream and the glass of cockle juice and mix well.
7: Add the cockles and chopped parsley. Stir again for 1 or 2 minutes, just long enough to reheat the cockles.
8: Serve immediately.
Remarks
You could also use other shellfish, such as mussels or clams. For a thicker, creamier sauce, add 1/2 ladle of starch-rich spaghetti cooking water to the cockle cooking juices in step 6.