White Asparagus with Beurre Blanc Nantais

Peel the asparagus from just below the tip to the base, removing all fibrous outer skin.

Mince the shallots very finely.

Cut the cold butter into 1 cm cubes and return to the refrigerator until needed.

Combine the shallots, Muscadet, and white wine vinegar in a small heavy-based saucepan and bring to a simmer over medium heat.

Reduce until only 2–3 tablespoons of syrupy liquid remain and the shallots are completely soft, until the mixture looks jammy and nearly dry.

Bring a large wide pan of water to a rolling boil over high heat, add the salt and sugar.

Lower the asparagus into the boiling water in a single layer and boil until a knife tip meets no resistance at the thickest part of the stem.

Lift the asparagus out with tongs, drain on a clean kitchen towel, and keep warm.

Add the cold water to the shallot reduction and reduce the heat to the lowest possible setting, so the pan base feels just warm to the touch — never hot enough to boil.

Whisk in the crème fraîche.

Begin whisking in the cold butter cubes two or three at a time, waiting until each addition is almost fully incorporated before adding the next, until the sauce thickens into a pale, creamy emulsion — never let it bubble or the emulsion will break.

Season the finished sauce with fine sea salt and white pepper.

Strain the sauce through a fine-mesh sieve for a smooth presentation, or leave the shallots in for a more rustic style.

Arrange the warm asparagus on warmed plates, spoon the beurre blanc generously over the spears, scatter with chervil or parsley leaves, and serve immediately with lemon wedges alongside.