To make the court bouillon, place all the vegetables with the thyme sprigs, bay leaf, peppercorns and wine in a large pot and bring to the boil. Cook for 5 minutes over high heat. Add the salt and 4litres water and return to the boil. Add the lobster tails, bring to the boil and cook for 12 minutes. Remove the pot from the heat and allow the lobster to cool slightly.
When the lobster is cool enough to handle, remove it from the bouillon. Discard the bouillon. Remove the tail in a single piece, following the method in the Chef’s techniques, then slice into medallions. Cover and refrigerate.
Wash the asparagus under cold, running water. Using a small knife, remove the spurs from the asparagus stems, starting from the top and working down, then remove the outer layer from the lower two thirds of the stem using a vegetable peeler. Lining up the tips, tie the stalks in bundles of six to eight, following the method in the Chef’s techniques.
Bring 4litres water to the boil. Add the extra salt and then the asparagus bundles. Reduce the heat to a gentle simmer and cook for 5–8 minutes, or until the tips are tender. Remove the bundles and plunge into iced water, then drain on paper towels. Remove the strings, place in a bowl, cover and refrigerate.
To make the dressing, whisk together the vinegar and shallot. Gradually whisk in the oils, then the chervil or chives. Season and set aside. Rinse the artichokes well, pat dry, toss them in a little dressing and season to taste. Repeat with the asparagus, being careful not to break the tips. Refrigerate the vegetables until ready to use. To serve, arrange the artichokes, asparagus and lobster medallions on serving plates. Drizzle the remaining dressing around the artichoke, then garnish with chervil.