01 - Preheat oven to 425°F. Line a baking sheet with parchment paper.
02 - Arrange asparagus spears on the prepared baking sheet. Drizzle with olive oil, then sprinkle with salt and black pepper. Toss to coat evenly and spread in a single layer.
03 - Roast asparagus for 12–15 minutes, or until tender and slightly golden.
04 - Meanwhile, prepare the hollandaise sauce: In a heatproof bowl, whisk together egg yolks and lemon juice until thickened and doubled in volume.
05 - Place the bowl over a saucepan of gently simmering water (do not let the bowl touch the water). Continue whisking constantly, slowly drizzling in the melted butter until the sauce is thick and creamy. Remove from heat and whisk in salt and cayenne pepper.
06 - Arrange roasted asparagus on a serving platter. Spoon warm hollandaise sauce over the top. Serve immediately.