If you are using chicken leg quarters, use a sharp heavy knife to cut between the joint so you end up with two pieces. Put the chicken pieces in a large saucepan with the lemon slices, star anise and ginger. Cover with cold water. Bring the water to the boil, then reduce to a simmer and parboil the chicken for 15 minutes. Drain, then sit the chicken on a cake rack over a roasting tin until it is cool enough to handle.
While the chicken is cooling, mix together the cornflour, vinegar and honey. Using your fingers, rub this mixture into the skin of the cooled chicken, allowing the excess to run off onto the tray below. Place the tray, uncovered, in the refrigerator overnight to allow the cornflour mixture to dry over the chicken skin.
To make the crumbs, place the slices of bread into a food processor and process for about 30 seconds, or until finely crumbled. Heat the oil in a large frying pan over a moderate heat, add the garlic and, if you are using it, the chilli and stir for 30 seconds, or until fragrant, watching carefully that it does not burn. Add the breadcrumbs and stir constantly for 6–7 minutes until the crumbs are golden and crisp. Remove from the pan and add the lemon zest and salt. Set aside until ready to use.
To cook the chicken, heat a wok or large, deep saucepan one-third full with oil over a moderate heat. There needs to be enough oil that the chicken should not touch the bottom of the pan during cooking, but should float slightly. Cook the chicken in batches in hot oil for 7–8 minutes, turning the pieces over halfway through cooking. When cooked the chicken should have a dark golden, crisp skin. Drain on paper towels.
To serve, place the chicken onto serving plates, or a large platter, and scatter with the garlic crumbs.