Of course, I have taken a bit of a liberty with the title of this recipe as this béarnaise sauce is not really instant but it is really quick and takes all the worry out of making an emulsion sauce. The Serious Eats website came up with the genius way of making mayonnaise and hollandaise sauce with a stick blender. I hardly ever make mayonnaise any other way now-mainly because I don’t have to wash up the food processor. It is foolproof BUT I cannot stress enough that you need the right container to make the sauce. Its diameter must be only slightly bigger than the head of the stick blender. Ideally, use the measuring container that are supplied with most of the stick blenders. If you get that right you’ll never look back. I didn’t have any fresh tarragon but you can substitute it for the dried –just up the quantity to one tablespoon.
- 1 ½ tablespoons cider vinegar (or white wine vinegar)
- ¼ teaspoon black peppercorns
- ½ teaspoon dried tarragon
- 2 egg yolks
- 1 teaspoon Dijon mustard
- ½ teaspoon English mustard powder
- 125g salted butter
- 125g unsalted butter
- Put the vinegar and peppercorns in a small saucepan and place over a high heat. Bring to the boil and reduce the liquid by half. Strain into a ramekin, discarding the peppercorns, and stir in the tarragon. Set aside.
- Put the egg yolks, mustards and 1 tablespoon cold water in the container in which you will mix the sauce (see intro). Put the two butters in a saucepan and melt over a low to moderate heat-don’t let it colour.
- When the butter is on the point of melting completely, start to blend the egg yolk mixture with the stick blender. Continue to blend at the same time as drizzling in the hot melted butter. Keep blending and drizzling until all the butter is used up-you can discard any of the milky solids that might be left in the bottom of the saucepan. The sauce should be really thick and emulsified. Stir in the vinegar/tarragon reduction and serve as soon as possible.