Preheat the oven to 220C/425F/Gas 7.
For the 'royal', pour the cream into a small pan and bring to the boil over a high heat. Add the goats' cheese and season with salt and freshly ground black pepper. Pour into a bowl, add the beaten eggs, whisk and pass through a sieve into an ovenware dish (this is called a bain-marie). Sprinkle the top with parmesan cheese.
Place the dish in a baking tray, and fill with boiling water to half-way up the sides of the dish and cook for 25-30 minutes.
For the jelly, heat the pineapple juice in a small saucepan over a medium heat. Place the gelatine leaf into a small bowl, cover with cold water and leave until softened. Drain off the water, squeeze out the excess and add the soaked gelatine leaf to the hot pineapple juice. Remove from the heat and leave to dissolve for 1-2 minutes. Stir well and then pour the jelly into a square tub to set. Once set cut into 2.5cm/1in squares.
For the pineapple, reduce the oven temperature to 130C/250F/Gas 1.
Submerge the pineapple in melted butter in a small baking tray and gently cook in the oven, turning frequently, for 10 minutes or until tender and then cut into 2.5cm/1in squares.
For the syrup, pour the pineapple juice into a non-reactive pan and simmer over a medium heat for five minutes or until reduced to a syrup. This should make around 200ml/7fl oz of syrup.
For the garnish, pour the vegetable oil into a large saucepan or deep fat fryer and heat to 180C/350F or until a small cube of bread turns golden in 30 seconds. (CAUTION: hot oil can be dangerous. Do not leave unattended.)
Carefully drop the watercress into the hot oil and fry for one minute or until crisp. Remove with a slotted spoon and drain on kitchen paper.
To serve, cut the goats' cheese 'royal' into pieces the same size as the pineapple squares and place on top of the pineapple squares. Place the jelly squares on top and stick a cocktail stick through the middle to secure. Place two goats' cheese 'royals' onto each of four to six plates, pour over the pineapple syrup and garnish with deep-fried watercress.