Preheat the oven to 160°C. Heat two-thirds of the honey with the water in a small, heavy-based saucepan, stirring as the honey comes to the boil. Reduce the heat to medium and watch carefully until it turns rich and golden. As soon as the colour deepens, remove from the heat and allow the bubbles to subside, then divide the mixture between 4 small ramekins. Warm the remaining honey, whisk in the eggs until just combined, then whisk in the milk, orange zest and cardamom. Pour the mixture evenly over the honey caramel in the ramekins. Place the ramekins in a bain-marie or roasting dish filled with water coming halfway up the outside of the ramekins, and cover the dish with aluminium foil. Bake for 20–30 minutes until the custards are just set. Remove from the water bath, cool, then refrigerate for 1–2 days. Remove from the refrigerator 1 hour before serving. Invert onto plates to serve.