Wash beet, wrap in foil (each separately) and in the oven for 40 minutes.
Pull out the finished beets, unwrap and allow to cool.
In this time preparing sauce. Put in a blender avocado, chopped celery and lemon juice, squeeze the garlic and scroll, then add the cottage cheese and yogurt, scroll again.
Cut the beets into slices and, alternating with the sauce, spread on arugula. Garnish with cherry tomatoes, celery leaves and pine nuts.