Use a mandoline slicer or vegetable peeler to cut the cucumbers into long, thin, even strips. Lightly salt the strips and allow to drain for a few minutes. Pat dry with paper towels.
Meanwhile, drain the tuna well and break into bite-sized pieces.
Top each cucumber slice with a small spoonful of Greek yogurt and a piece of tuna. Roll up carefully and secure with a toothpick.
Arrange the rolls on a serving platter and season with a sprinkle of black pepper and a light drizzle of olive oil.
For added flavor, serve alongside a fresh tomato salad.