Begin by whisking egg yolks in a stainless-steel mixing bowl. Add lemon juice into the mixing bowl and continue to whisk vigorously.
2. Melt the Butter
Melt unsalted butter either in the microwave or on the stovetop. Set aside.
3. Prepare the Double Boiler or Pot of Simmering Water
Add cold water into a pot (or the base of a double boiler) and place it on the stovetop at medium heat. Bring to simmer.
Place the mixing bowl (or upper pot of the double boiler) over simmering water.
4. Continue Whisking over the Hot Water while Adding Melted Butter
Continue to whisk. Ensure that the sauce does not overheat. Otherwise, the eggs may scramble.
Drizzle melted butter slowly into the mixing bowl. Continue to whisk.
Whisk in thyme leaves, salt, and ground pepper.
5. Allow Hollandaise to Double in Volume
When the hollandaise doubles in volume and generously coats the back of a spoon, it is done. Pour mixture into another (cool temperature) bowl and set aside.