Overly buttery hollandaise?
Many recipes call for different ratios of egg yolk to butter. Egg yolk size can vary substantially. Your recipe is definitely at the low egg/high butter end of the spectrum.

Considering it came out looking great, add another egg yolk next time, and another the time after that.

I like 3 yolks with half a stick of butter, made with USDA AA large eggs, cooked sous vide (no double boiler).