Eggs and lemon juice, whisked. Add warm(liquid)butter slowly. Pinch paprika, and presto. Note that the sauce has not been put over heat of any kind; relying on the heat of the butter to thicken. Well the sauce was kind of runny. I saw it on 'The Kitchen' today. I've always made a hollandaise sauce over direct heat being careful with the heat. Taking it off the burner once in a while if it needs it. Also, I've never used lemon juice, substituting white wine. And also adding a pinch of cayenne. And aromat seasoning. They pointed out that this sauce was difficult to make. It's not. You just need to be careful not to break it, or to not scramble the eggs.