Boil the lobster in a large pot in plenty of simmering water for about 2-3 minutes. Break off the claws and cook the lobster for another 2-3 minutes. Let cool until lukewarm. Break off the lobster and refrigerate the meat, covered. Cut the avocados in half, remove the seeds and scoop out the flesh. Grate with a coarse potato grater or mash with a fork. Immediately marinate with lemon juice and season with sea salt. Briefly scald the tomatoes, peel, seed and cut into small cubes. Mix into the avocado mixture. Mix the toasted pine nuts with tarragon vinegar, olive oil and safflower oil to make a vinaigrette. Chop the meat of the lobster claws and joints, mix with finely chopped tarragon and season with a little vinaigrette. Now, in a tall cookie cutter about 5 cm in diameter (or a small serving dish), alternate avocado mixture and lobster tartare. Chill for about 1/2 hour. Marinate the broken out lobster tail with vinaigrette and portion. Place one tartlet on each plate (pull off ring mold) and place one piece of lobster tail on each. Serve at room temperature.
COOKING TIME: 4-6 minutes total TIP: Don't let the lobster get completely cold, as a lukewarm lobster is easier to break out.