Clean shellfish shells and remove beards from mussels while discarding any open shells.
Cook seafood with white wine in a hot, covered pan for 3 minutes and discard unopened shells.
Strain and reserve cooking liquor then chop white razor clam flesh into 2cm pieces.
Sauté samphire in 12.5g of butter for 2 minutes and season with pepper.
Fry shallot and garlic in remaining butter before adding liquor and cream to reduce by half.
Add seafood, tomatoes, and lemon juice to the sauce and warm through.
Spoon sauce over the samphire and garnish with red seaweed.