Using a vegetable peeler, slice cucumber into thin flat strips. Lay slices down on paper towels to drain excess moisture.
On a cutting board or clean work surface, lay two slices on top of each other. Spread a thin layer of hummus on top of each slice, then sprinkle feta, kalamata olives, and cherry tomatoes on top.
Tightly roll each cucumber slice. Stick a small sprig of dill into each sushi piece. Squeeze fresh lemon juice on top, if using.