01 - Preheat oven to 425°F. Line a baking sheet with parchment paper.
02 - Arrange asparagus in a single layer on the prepared baking sheet. Drizzle with olive oil, then sprinkle with salt and pepper. Toss to coat evenly.
03 - Roast asparagus for 12–15 minutes, or until tender and lightly browned.
04 - While asparagus roasts, prepare the Hollandaise sauce: In a heatproof bowl, whisk together egg yolks and lemon juice until thick and pale.
05 - Set the bowl over a saucepan of gently simmering water, ensuring the bowl does not touch the water. Whisk constantly while slowly drizzling in the warm melted butter until the sauce thickens and doubles in volume.
06 - Remove from heat. Season with salt and a pinch of cayenne pepper, if desired.
07 - Plate roasted asparagus and spoon Hollandaise sauce generously over the top. Serve immediately.