Add the base mayonnaise, dill, and parsley to a tall jar — no need to chop beforehand, the immersion blender will break them down.
Blend on high speed in short bursts, moving the blender through the full depth of the jar, until the herbs are fully incorporated and the mayo turns a light, even green.
Taste and adjust the seasoning with salt and white pepper as needed. Transfer to an airtight jar and refrigerate until ready to use.
Chef's Tips
Blend in short bursts rather than one long continuous blend — pushing it too hard and too long can heat the mixture through friction, which dulls the herbs' colour and can turn the flavour slightly bitter.Push the blender down through the whole depth of the jar as you go — this makes sure the herbs get fully broken down and evenly distributed rather than staying concentrated near the top.Taste and adjust the seasoning at the end, as written — fresh herbs vary a lot in intensity batch to batch, so this step matters more here than in a plain mayo.
Storage & Reheating
Refrigerate for up to 4 days in an airtight jar or container. Freezing isn't recommended, since the raw-egg base will split once thawed. No reheating required — this one's served cold.