Peel and segment the grapefruits, catching some of the juice for the dressing.
Add grapefruit, onion, scallions, olives, sauerkraut and herbs to a large bowl.
Whisk together olive oil, grapefruit juice, sauerkraut juice, vinegar and sumac and pour it over the salad.
Gently toss everything together so the dressing coats the ingredients.
Transfer to a platter for cute arrangement.
Optional: crumble a little feta on top.
