Griddled asparagus with poached duck egg and chervil hollandaise sauce
Bring a pan of salted water to the boil, add the asparagus spears and blanch for 1-2 minutes.
Drain well, return the asparagus spears to the pan, off the heat, and drizzle over the olive oil. Shake the pan to coat the asparagus spears, then season, to taste, with salt and freshly ground black pepper.
Meanwhile, heat a griddle pan over a medium to high heat. When the pan is smoking, add the seasoned, blanched asparagus and griddle for 3-4 minutes, or until tender.
Add the butter to the pan and, when foaming, shake the pan to coat the asparagus spears in the butter.
In a separate, non-reactive pan, heat the lemon juice and white wine vinegar until just boiling.
Place the egg yolks and a pinch of salt into a food processor. Set the motor to run slowly, then gradually add the hot lemon and vinegar mixture to the egg yolks in a thin stream, until all of the mixture has been incorporated into the egg yolks.
With the motor still running, gradually add the melted butter to the mixture in a thin stream, until completely incorporated.
Add the chervil to the hollandaise sauce and season, to taste, with salt and freshly ground black pepper. Set aside and keep warm (cover the mixture to prevent a skin from forming on the surface).
Bring a small pan of water to a gentle simmer.
Stir the simmering water vigorously to create a vortex, then carefully crack two of the duck eggs into the water. Poach for 2-3 minutes, or until the eggs are cooked to your liking, then carefully remove from the pan using a slotted spoon and set aside to drain on kitchen paper.
Repeat the process with the remaining two duck eggs.
To serve, divide the asparagus spears equally among four serving plates. Place one poached egg on top of each serving of asparagus. Drizzle over the chervil hollandaise sauce. Serve immediately.