Cut the stick into approximately ½-inch cubes. You should have roughly 8 cubes.

Don't melt the butter. That's the whole idea.

Fill a small saucepan with an inch or two of water and bring it to a bare simmer.

Set a heatproof bowl over the saucepan, making sure the bottom of the bowl does not touch the water.

You want gentle steam—not boiling water.

If the water is aggressively bubbling, turn down the heat.

Add the 4 egg yolks and 1 tablespoon lemon juice to the bowl.

Whisk together for about 30 seconds, just until the yolks become slightly lighter and begin to thicken.

Add a few dashes of Tabasco.

You're warming the yolks—not scrambling them.

Now for the part that breaks the rules.

Add one cold butter cube to the warm yolks.

Stir continuously but gently with a whisk until the cube softens and disappears into the yolks.

Don't whisk aggressively.

Once the first cube has incorporated, add another.

Continue adding the butter one cube at a time, allowing each cube to incorporate before adding the next.

The process should be deliberate rather than rushed. Each cube will take roughly 15–20 seconds to soften and incorporate.

As you add the butter, the sauce will gradually change.

At first, you'll have relatively loose yolks. As more butter is incorporated, the sauce becomes:

thicker → glossier → richer → more structured

Around the sixth or seventh cube, you should see the emulsion really come together.

Continue until all 8 tablespoons of butter have been incorporated.

This is where the cold-butter method really earns its keep.

If the sauce becomes too thick or the bowl begins to feel too hot, lift the bowl off the bain-marie for a few seconds while continuing to stir.

The residual heat in the bowl will continue melting the butter without continuing to cook the yolks.

Return the bowl to the bain-marie when necessary.

The goal is gentle heat, not high heat.

Dip the back of a spoon into the finished hollandaise.

The sauce should coat the spoon in a thick, even layer.

Run your finger through it.

The line should hold.

If it's too thick, a tiny amount of warm water can loosen it. If it's too thin, continue gently stirring over the bain-marie for a little longer.

Taste and adjust with additional:

Salt

Lemon juice, if needed

Tabasco, if you want more heat

Keep the finished hollandaise warm over—not directly on—the bain-marie until you're ready to serve.