Cut the beets into smaller cubes
Remove the skin from the avocado and cut it into bite-sized pieces.
I usually "shred" the feta into smaller pieces with my hands.
Mix all ingredients in a bowl and the salad is ready.
If you feel it lacks a bit of acidity, you can add a little lemon juice to the salad.
Keep the display on
Notes
See, for example, a recipe for pickled beets here.