Cut the iceberg lettuce into bite-sized pieces and wash. Dice the feta cheese. Wash, core and dice the apple. Toast the sunflower seeds in a non-oiled pan until they are light golden brown.
Mix the yogurt, milk, vinegar and oil and season with salt, pepper, sugar and paprika. Stir in the finely chopped onion.
Add the cleaned iceberg lettuce, apple and feta cheese and mix everything together. Finally sprinkle the roasted sunflower seeds over the top.