Place the black beans, tahini, garlic and lime juice into a food processor. Process until combined and smooth. Slowly drizzle in the oil while keeping the processor going. Season and give it a final whizz, then pour it into your serving bowl of choice.
Place the yogurt in the corner of a small sandwich bag and cut a tiny piece from that corner. Pipe the yogurt on to the houmous in evenly spaced circles resembling a bullseye, then straight lines to create the web.
Cut the olive in half lengthways. Take one half and cut that into two widthways. Position one of these cut side down on the houmous and use the remaining olive pieces to cut tiny strips into spider legs. Position them around the olive half.