All you need is a cucumber, an avocado, (soy) yogurt and sesame seeds.
Mash the avocado and mix it with a heaping tablespoon of (soy) yogurt. Cut the cucumber in long thin slices. Put a tablespoon of the avocado mixture on a slice of cucumber and roll it up. You can use a cocktail stick to keep it together if the avocado dip isn’t sticky enough. Dip one side of the snack in sesame seeds, so that they stick to the avocado mixture. Serve them on a plate or board with the sesame side up.