1tablespoonchampagne vinegar or white wine vinegar"O" brand is great if you can't find the real deal, with a capital C
¾ cupolive oilCalifornia Olive Ranch is a good one
1tablespoonfresh tarragon leaves, minced
apinchsalt
Instructions
Blend the egg yolk with the mustard and vinegar in a blender or food processor. With the machine running, add the oil in a slow, thin stream. Mix in the tarragon and season with salt. Keep refrigerated and use within a week or so.