Boil the Charlotte potatoes in salted water for 20-25 minutes until tender. Drain well.
Meanwhile, gently flake the crab meat into a bowl. Grate the lime zest over it, add 1 tablespoon lime juice (note: source specifies lemon, but lime zest suggests lime), 15 cl cream, and chopped chives. Mix delicately to combine flavors.
Preheat oven to 210°C (thermostat 7).
Peel the warm potatoes and pass through a potato ricer or masher. Incorporate the butter, stir until melted, then add remaining cream, salt, pepper, parsley, thyme, and marjoram. Mix until smooth and creamy.
Spoon half the mash into a buttered baking dish, spreading evenly. Layer the crab mixture on top, then cover with remaining mash, smoothing the surface for a neat finish.
Bake for 10 minutes until golden. Serve hot or warm for best texture and flavor.
