Fold a double piece of tinfoil in half and seal up the two sides to make a little bag. Cut a fennel bulb in half and then into slices and add these to your tinfoil envelope. Squeeze in the juice of ½ a lemon, leaving the lemon half in the bag. Add ½ a sliced fresh red chilli and a good drizzle of olive oil, then season with sea salt and freshly ground black pepper. If you want, you could add a few bits of fresh rosemary. Seal the last edge tightly and place on the bars over a medium hot barbie until cooked. This should take about 25 minutes.