Slice the pea gel into 1.5 cm (⅝ inch) cubes. Lay plastic wrap over a small dariole mould and depress the centre slightly. Pipe 10 g (⅓ oz) of the black sesame purée onto the plastic wrap and place a cube of pea gel on top. Pipe another 10 g of black sesame purée on top, making sure the pea gel is completely covered and there are no air pockets. Take all 4 corners of the plastic wrap, twist together to form a tight ball and tie tightly to secure. Repeat to make 18 balls.
These can be made 1 day in advance and refrigerated. When ready to serve, heat a saucepan of water to 90°C (194°F) and poach the balls for 3 minutes. Scoop out and remove the plastic wrap. Serve immediately.