Preheat the oven to 200°C. Cut each sheet of puff pastry into quarters and place on a parchment-lined baking sheet. Place a second sheet of baking paper and a baking sheet on top, to help the puff pastry rise evenly. Bake in the middle of the oven for 20 minutes, remove the baking tray and parchment paper and bake for another 5 minutes until golden brown. Cool on a wire rack.
Heat a frying pan and toast the pine nuts over medium heat for about 3 minutes until golden brown. Cool on a plate.
Cut the avocados all the way around the stone. Twist the two halves apart. Remove the stone and scoop the flesh out of the skin. Slice the flesh into chunks. Squeeze the lime. Roughly slice the garlic and the shallot.
Puree the avocado, garlic, shallot, lime juice and crème fraîche in the blender, or blend with the hand blender, until you have a smooth cream. Season with salt and pepper. Transfer the cream to a piping bag.
Pipe a dollop of avocado cream onto four pieces of puff pastry, followed by some rocket. Divide half of the carpaccio on top. Brush with a little truffle mayonnaise and sprinkle with some Grana Padano and pine nuts. Repeat and finish off with the last pieces of puff pastry. Pipe a dollop of avocado cream on top and sprinkle with the rest of the pine nuts and Grana Padano.
Vegetarian tip Not a fan of meat? This is also a lovely starter without the carpaccio. Add another avocado and ½ tbsp crème fraîche, and use the whole shallot. Tip: Decorate the slice with finely chopped sweet pepper or a cherry tomato.
