Fill a shallow pan or dish with an inch of warm water. Dip one rice paper wrapper into the water for a few seconds, fully submerging, and then remove, allowing excess water to drip back into the pan. Lay the wrapper on a clean cutting board. Place a butter lettuce leaf in the center of the wrapper, then add a small pile of tofu, carrots, peppers, cucumbers, green onions and cilantro. Fold the bottom edge of the wrapper over the top of the ingredients, tuck in the edges, and roll closed, like a burrito.