Peel the shells off the langoustine tails and chop them. Season them with salt, pepper, and fresh thyme afterward.

The chicken skin should be gently removed from the whole chicken and set aside. In this case, we didn't need the chicken, so it was cut and divided for later use - as shown in this video.  

The skin should be placed on plastic wrap with the outside facing down and sprinkled with meat glue.

The haddock fillet should be placed on top and sprinkled with meat glue. The langoustine stuffing goes on top, and another haddock fillet is placed over it. 

Again, sprinkle with meat glue and close the skin around the fish.

Wrap the plastic wrap tightly around the ballotine, rolling it up like a sausage.

Prick a few holes in the sausage, and wrap it again in plastic wrap. The ends should be tied with string to ensure no liquid gets in. Then, cook it for 1 hour at 49 degrees Celsius (120 degrees Fahrenheit) in a sous vide/water bath. 

Carefully unwrap the ballotine and pat it dry. Fry it for 5-7 minutes in a deep fryer until the skin is crispy. 

Then, cut them into slices approximately 2 cm thick and serve immediately. Remember to cut the slices in half and place them meat side down to ensure the skin remains crispy. 

Cut the cauliflower into small pieces and cook it in 1/3 water, 1/3 milk, and 1/3 cream for about 20 minutes until tender. Then strain the cauliflower and blend it with a bit of the cooking liquid, salt, white pepper, a bit of lemon, and vinegar. Add enough liquid so the mixture can pass through a very fine sieve and into a siphon. Charge the siphon with one cartridge and place it in the sous vide/water bath until serving time.

At serving, charge the siphon with another cartridge, shake it vigorously before pushing out the foam.

Serve the dish with a slice of pickled red onion.