Fool Proof Hollandaise

1. In a jar or cup that just fits around the head of the blender (500ml wide mouth mason jar works great) combine the egg yolk, lemon juice, warm water, and salt. 

2. Cut butter into small chunks and melt over medium high heat until foamy, careful not to burn or brown. Transfer to a measuring cup, slowly so it doesn't rise up and spill foam over the top. Let it sit for a minute to cool a bit otherwise you risk cooking the yolk. 

3. Blend the contents of the jar for a few seconds, and with the blender still running add the melted butter at a slow trickle, lifting the blender if needed to help mix it in. Continue until all the butter is mixed. Taste, adjust seasonings. Give yourself a pat on the back. 

Tip: Prepare everything else first, this is quick to make and its best not to have it sitting around cooling, but if you need to keep it warm a shallow pan of hot water, at the same level as the sauce, did the trick. 

Source: https://www.seriouseats.com/re...