Put a pot of water on the heat and bring it to the boil, once it has reached a rolling boil add the lobster with half a teaspoon of salt. Boil the lobster for 8-10 minutes, until it's cooked all the way through, the shell turning orange is a natural indicator of this.
Put another pan of water onto the heat and bring to the boil. Break the ends off the asparagus stems and put them into the boiling water, cook them for two minutes so that they are tender but still crunchy. Then remove them from the boiling water and plunge them into a bowl of ice cold water, this will help them to retain their colour and freshness.
Put a frying pan onto the heat with some olive oil in, add the capers and fry them for two minutes, until they begin to open and become crisp, set them aside till needed, then put them onto a plate until you are ready to serve.
For the mayonnaise, place the Dijon mustard into a food processor, add the egg yolks, crushed garlic, juice and zest of one lemon and a pinch of salt, then blitz together. Whilst continuing to mix, add a drop of olive oil, then very slowly add more olive oil, keeping a long, steady flow, continue to add the oil until it reached the desired consistency. Place the mayonnaise into a bowl and add the tarragon, dill and some freshly ground black pepper and mix well.
Take the cooked lobster, remove the claws and tail and put them to one side to use as a garnish for the final dish. Remove the flesh from the body of the lobster, making sure that you remove the digestive tract; it's a great idea to keep the lobster shell and freeze to make a wonderful stock for a bisque at a later time.
Slice the lobster tail and keep it to one side until you are ready to serve.
Cut the avocado in half, remove the stone and peel the avocado.
To assemble the dish, place the asparagus onto a large plate or platter, lay the avocado slices on top, followed by the lobster, dress with some mayonnaise and then top with the capers. Then place the lobster head and claws to the side for an extra flourish.