Remove the peel from the oranges so that the white skin is completely removed. Cut oranges diagonally into 5 mm thick round slices and spread out on a large platter. Gut the crab tails if necessary. Heat 3 tbsp olive oil in a large frying pan. Sauté crayfish tails in it, turning, for 2-3 minutes. Season well with salt and cayenne.
Remove from frying pan and place in a suitable bowl. 2.
Clean the peppers, cut them in half lengthwise, remove the seeds and cut into very fine cubes. Dice the onion very finely as well. Stir together the salt, vinegar, pepper, 1 pinch of sugar and the remaining olive oil to make a sauce. Mix half of the sauce with the diced peppers, diced onion and crab tails and cover with a lid for 15 minutes.
3. cut the olives into wedges from the stone. Rinse the arugula and spin dry. Evenly distribute the crab tails and black olives on the orange slices. Garnish the leaf salad with arugula and drizzle with remaining dressing.