Preheat your oven to 400°F. Trim the woody ends off the asparagus spears (usually about 1-2 inches from the bottom). Divide the asparagus into 4 bundles of 3-4 spears each. Wrap one bacon slice tightly around each bundle, ensuring it holds everything together. Arrange the bundles on a baking sheet with the seam side of the bacon facing down so it stays secure while roasting.

Drizzle the asparagus bundles with olive oil and sprinkle with sea salt and freshly cracked black pepper. I like to use my hands to lightly coat everything evenly for better flavor development. Roast in the preheated 400°F oven for 15 minutes until the bacon is crispy and the asparagus is tender but still has a slight bite to it.

While the asparagus roasts, melt the unsalted butter in a small saucepan over medium-low heat—you want it melted and warm but not sizzling or browning. Keep it at a gentle temperature throughout. This timing allows you to have everything ready just as the asparagus finishes cooking.

Add the egg yolks, freshly squeezed lemon juice, and salt to a blender. Blend on low speed for about 30 seconds until the mixture becomes pale and slightly foamy. With the blender still running on low speed, slowly drizzle in the warm melted butter from Step 3 in a thin, steady stream—this gradual incorporation is key to creating a silky, stable emulsion. Once all the butter is incorporated, add the cayenne pepper and pulse briefly to combine. I find that freshly squeezed lemon juice makes a noticeable difference in the sauce's brightness compared to bottled juice, so it's worth the extra squeeze!

Remove the roasted asparagus bundles from the oven and immediately transfer them to serving plates while they're still hot. Pour the hollandaise sauce generously over the top of each bundle, allowing it to cascade down the sides. Serve immediately while everything is at its peak temperature—the warmth of the asparagus and bacon will complement the rich, buttery sauce perfectly.