Clean and wash the leek and cut into fine rings. Blanch in boiling salted water for about 2 minutes. Then rinse with cold water and drain. Clean, wash and cut the peppers into fine strips. Mix lemon juice and olive oil. Season with salt, pepper and sugar and drizzle over the prepared vegetables. Finely dice the feta cheese and mix with the yoghurt.
Season with pepper. Peel garlic and cut into thin slices. Fry in 1 tablespoon of hot oil until golden brown. Take out and let drain. Layer marinated vegetables and yoghurt alternately in glasses. Serve sprinkled with olives and garlic as desired