If necessary, peel and quarter the cucumber and remove the seeds. Peel and quarter the onion. Cut the cucumber and onions into slices. Wash the mint, shake dry, pull off the leaves and chop finely. Mix everything with the pomegranate seeds in a bowl. Season with lemon juice, salt and pepper. If you want, refine it with yogurt or olive oil.
Let it steep for 1 hour and enjoy with fish (e.g. tuna steak), grilled meat or at the party buffet.