Blanch the asparagus for a few minutes until tender. Drain and season well. Slice the potatoes, then toss in olive oil and season with salt and pepper.
To make the dressing, start by boiling the eggs for 3 minutes. Quickly break the runny yolk into a food processor, add the shallots and herbs, and blitz them all together. Don’t throw away the cooked egg whites. Slowly pour in the two oils to make an emulsion, season and add lemon juice to taste. Chop the cooked egg whites finely and stir into the dressing.
Arrange the asparagus on a serving plate with the potatoes, salad and crab, and drizzle with some of the dressing, leaving the rest on the side.
This dressing method is almost foolproof and the emulsion shouldn’t split if you boil the egg for a few minutes