Immediately drizzle the lemon juice over the avocado slices to prevent them from browning.
For the dressing, whisk all ingredients together well.
Arrange the beetroot, avocado and egg slices alternately on 2 plates like a roof tile. Drizzle the dressing over it and sprinkle the chives on top. Decorate with the flaked almonds.
You can also buy beetroot already cooked and vacuum-sealed (better than in a jar).