Cut the avocadoes in half and remove the pit. Scoop all the flesh into the bowl of a blender or food processor.
Cut one end off the apple half, and place it in a bowl, cut side down, with 1 teaspoon lemon juice – you’ll use this to make little matchsticks for the decor. Peel and seed the rest of the apple, and add it to the avocado.
Blend or process the avocado and apple, then add 2 teaspoons lemon juice, vegetable stock, and salt. Carefully blend or process again. Cool completely, and refrigerate for 1 hour. (Any longer than that, and the avocado will begin to turn brown and a little bitter.
When you’re ready to serve, reserve 4 pretty cilantro leaves, and finely chop the rest. In a medium bowl, mix together with a fork the chopped cilantro, crab meat, olive oil, the remaining 1 teaspoon lemon juice, and salt and pepper.
Gently pour or spoon the avocado puree into 4 cocktail glasses, and then very gently spoon about ¼ cup of crab on top of each portion. Finely slice the piece of apple you reserved in the lemon juice to make 8-12 matchsticks (or cut them in the shape of your choice). Place them on top of the crab, and decorate with the cilantro leaves. Bon app’!