Season the langoustines and scallops and in a heavy bottom pan heat some olive oil. Sear the langoustines and scallops in the hot oil and remove to a plate. Place into the same oil the crushed garlic clove, dried chilli and 1 branch of basil plus the stalk of the other. Then add the chopped tomato and fry for about 2-3 minutes to break down the tomato mashing with a spoon. Then season with salt and pepper.
Add the mussels and a splash of white wine and cook to open the mussels at the same time reducing the wine. Pour in the cream but do not mix. Allow to cook down a little further. Return the seared scallops and langoustines to the pan. Check the seasoning. Add the cooked pasta, toss and add the remaining basil season with a squeeze of lemon and serve.