Season the Foie Gras with the salt, Madagascan pepper and rum, and leave to marinate for 12 hours.
Prepare the pineapple, cut into 4 pieces lengthwise and remove the core. Dry out the pineapple in the oven for 15 minutes at 200°C, then set aside.
Half-fill a terrine with the marinated Foie Gras, arrange the segments of dried pineapple, perfectly centred, and finish the terrine with the rest of the Foie Gras.
Seal the terrine in a vacuum bag and cook in a steam oven for 1 hour 15 minutes at 74°C.
Leave to rest for 48 hours.
2 hours before serving, peel and cut the celeriac into sticks the size of your little finger.
Caramelise the honey in a frying pan and add the sticks, taking care to coat them well. Deglaze with the veal stock and then reduce to a syrupy consistency.
Add the coarsely ground peppercorns and then set aside at room temperature.
When ready to serve, place 1 slice (50 g) of Foie Gras in the centre of a plate. Arrange the sticks of caramelised celeriac in a lattice design.
To decorate, place some dots of the remaining caramel.