Melt the butter over a low flame until it begins to bubble.
1/4 lb butter
Remove from heat.
Put the egg yolks, lemon juice, salt and pepper in the jug of an electric blender.
3 large egg yolks, 1 pinch salt, 1 pinch ground pepper, 2 tbsp lemon juice
Cover and blend on high speed for about 5 seconds.
Remove the cover and add the butter in a slow stream, blending at high speed for approximately 30 seconds more.
The sauce should be smooth with no traces of unincorporated butter.
Pour the sauce into a small bowl and whisk in the ketchup and Tabasco sauce.
2 tbsp ketchup, Tabasco
Notes
For entire recipe. Don't forget to divide by the number of servings.image curtesy of Stacy Spensley at https://www.flickr.com/photos/notahipster/5237117618