Mix yoghurt with juice and oil. Season to taste with salt, pepper and sugar. Wash and clean the cucumber and dab dry. Cut lengthwise into thin strips with a peeler. Drizzle cucumber with the sauce.
Wash the herbs, dab dry. Put some aside for garnishing. Sprinkle herbs on the maties, roll them up and pin them with wooden skewers. Arrange the matie rolls on the salad. Garnish with remaining herbs and lemon.