For the vinaigrette, whisk 4 tablespoons of white wine vinegar, salt, pepper and sugar. Fold in the oil well. Peel the shallot, cut into fine cubes and stir into the vinaigrette.
Rinse the crayfish meat and pat dry. Wash and quarter the tomatoes. Cut the avocado in half lengthwise and remove the stone. Remove the flesh from the skin with a spoon and cut into bite-sized cubes.
Mix immediately with the vinaigrette, crayfish meat and tomatoes. Sort the salad, wash and shake dry.
Bring 1 1/2-2 l water to the boil in a wide saucepan. Add vinegar. Poach the eggs, lift them out and let them drain well. Fold the salad mix into the avocado salad and arrange the eggs on top. Baguette goes well with it.