By Alice Hart
White asparagus is grown in darkness below the soil surface to keep it blanched of colour, and the resulting spears are delicately flavoured. Some people add sugar to the cooking water to prevent bitterness, but simmering the asparagus in diluted milk has the same effect without the sweetness.
Start by making the beurre blanc reduction. Place the shallot, peppercorns, tarragon and Champagne or dry white wine in a saucepan and bring to the boil. Simmer the liquid down slowly for a few minutes until reduced by two-thirds. Strain through a sieve into a heatproof bowl.
Carefully pare away the skin from the asparagus stalks (but not the tips) using a vegetable peeler, treating the