Crunchy radicchio and almond salad

Method

1. For the mayonnaise, crack the egg into the bowl of a mini food processor and add the lemon juice, salt and mustard. Whizz to combine. Put the oils in a jug and, with the motor running, drizzle them in, starting with just a few drops at a time, then in a thin stream, until emulsified and creamy. (If you don’t have a mini food processor, use a bowl and an electric hand mixer, or whisk by hand.)
2. Stir in the parsley and season to taste with lemon juice and/or salt if it needs it. Put the dressing into a portable, sealed container, then chill or pack into a cool box with ice packs until ready to serve.
3. Cut the celeriac in half, thinly slice it and the radishes using a sharp knife (or a mandoline if you have one), then put into a large portable container. Thinly slice the radicchio, then toast the almonds in a dry pan for 1-2 minutes, shaking often, until just lightly golden. Roughly chop the almonds, then add the radicchio and almonds to the container.
4. Thinly slice the celery and add to the container with the grapes, then seal. To serve, shake the dressing, then pour most of it over the salad and toss to coat evenly. Taste and add extra if needed.