Using a sharp knife, slice the avocado thinly from top to bottom. You can also slice horizontally if you prefer a different texture or look. Once sliced, brush or lightly rub each piece with lemon juice to keep the vibrant green color from fading.

Lay the avocado slices carefully over the top of a prepared sushi roll, slightly overlapping each slice to form a smooth, continuous layer. Half an avocado is typically enough to cover one full roll. Adjust placement so that the avocado drapes evenly across the surface, creating a clean, polished finish.

Place a sheet of plastic wrap (Saran wrap) over the avocado-covered roll. Using gentle pressure with your hands, press down so the avocado adheres to the sushi, forming a seamless topping. Avoid pressing too hard to prevent squashing the roll or displacing the fillings.

With the plastic wrap still on, wet the blade of a sharp knife to ensure smooth, clean cuts. Slice the roll into eight even pieces, rewetting the blade after each cut to maintain precision and prevent sticking. Once cut, carefully remove the plastic wrap. Arrange the slices neatly on a serving plate.

Serve immediately, showcasing the vibrant avocado topping. Pair with soy sauce, wasabi, or pickled ginger for a beautifully fresh and creamy sushi experience.