Step 1

To make the dressing, whisk all the ingredients together in a bowl with some seasoning or place them in a screwcap jar and shake well. Can be made up to 2 days in advance. Cook the potatoes in plenty of boiling water for 10 mins until just tender. Drain, cool slightly, then slice.

Step 2

While the potatoes are cooking, blanch the green beans in plenty of boiling water for 4 mins until cooked but still with a slight crunch, drain, refresh in iced water to stop them cooking further, then drain again. Cook the quail’s eggs for 3 mins. Drain, place under cold water, then peel and halve. Flake the salmon into large chunks into a bowl and slice the spring onions. All these jobs can be done in advance. Just before serving, halve, peel and slice the avocados.

Step 3

This is a layered salad rather than a tossed salad, so start by scattering the watercress and chicory over a platter. Scatter different handfuls at a time of all the other ingredients (but not the mustard cress) so that they are evenly distributed. Drizzle over two-thirds of the dressing, then strew over the mustard cress. Serve with the remaining dressing on the side.