Thoroughly wash the clams.
Chop the shallots into a fine dice and cook in the butter until soft, when soft add the chopped garlic and 1 glass of the white wine and reduce slightly. This can be done up to 2 to 3 days in advance, cooled and kept in a sealed jar.
Place a large pan on the gas and allow this to get hot, adding the clams and the remaining white wine.
When they all start to open add the cooked spaghetti / linguine to the same pan. Then add the double cream and the cooked shallot mixture.
After 2 to 3 minutes when it is all warmed through, check the seasoning and adjust if necessary and add some of the chopped parsley.