Whiz up butter, salt tarragon, parsley, garlic and a dash of pastis until it’s nice and green.
Rub the fish with olive oil and sea salt and roast or grill for 5 minutes, add the shellfish give it another 4 – 5 minutes. Meanwhile put the eggs and water in a bowl and whisk until they double in size and are full of bubbles, over a gentle heat drizzle in the butter as if you were making mayonnaise, season with lemon juice and salt and pepper, add any juices from the fish. Arrange the fish on a plate; spoon over some of the sauce then put the whole plate back under a hot grill until it just browns. (Be careful this takes only a minute or so and can burn easily.) Melt the garlic butter and then spoon this over the top of the now glazed seafood.