Cook the buckwheat for 10 minutes in a large volume of salted boiling water. Drain it and let cool.
Steam the broccoli florets for about ten minutes.
Cut the cucumber and tomatoes into small cubes after removing the watery part.
Chop the fresh herbs and the scallion onion which you will have kept the green.
Place the vegetables in a container and add a little oil and vinegar. Add salt and pepper. Mix well.
Cut the avocado in half. Remove the core and empty with a spoon. Cut into small cubes.
Heat a large volume of water. When it boils, immerse the eggs and cook them for 4 minutes 30 to 5 (for large eggs).
Cut the cooking by immersing them in a bath of ice water.
Arrange the crushed buckwheat on the plates, then diced avocado, broccoli florets and the salad of cucumber, tomatoes, scallion and fresh herbs.
Crumble the feta and generously sprinkle the salad.
Shell the eggs, quickly cut them in half and place them in the middle of the plates.
Sprinkle the egg with fleur de sel from Guérande and the entire plate with the remaining herbs.
Mix the rest of the oil and apple cider vinegar and pour over the salad. Serve immediately!