When truffles are good they’re amazing, and worth the expense. A truffle without aroma is an extravagance that no one should afford. When stored correctly a truffle can hold its aroma for a week or two, but like so many things, fresh is best. Moisture is the enemy, so wrap your truffle in absorbent paper and store in an airtight jar in the crisper. Changing the paper towel regularly is also a good idea.
Pre-heat a griddle pan or a barbecue grill. Season and oil the asparagus. Grill, rotating the spears regularly to cook evenly. They should take two to three minutes to cook.
Lift the cooked asparagus off the grill and arrange the spears on a serving plate, check seasoning and adjust if necessary. Spoon over the mayonnaise and top with red veined and regular sorrel. Using a microplane, grate over the parmesan and add a squeeze of lemon. Top with fine shavings of truffle and serve immediately.