Combine the avocado, lemon juice, chives, salt, and pepper in a food processor and pulse until blended. Turn the processor on constant speed and slowly drizzle in the olive oil.

Using a mandoline or vegetable peeler, slice the cucumber lengthwise into 8 thin strips.

Spread the avocado mixture on each cucumber slice, then top each with a thin layer of smoked salmon and roll them up. Serve immediately.