Iron eggs

Step 1: Put 30 quail eggs in a pan of cold water, bring to the boil and simmer for 4 minutes, until hard-boiled. Cool in cold water and peel.

Step 2: Put ¾ cup tamari (gluten-free soy sauce), 2 cups water, 2 ⅛ oz rock sugar, 2 star anise, 1 tsp five-spice powder, 1 tbsp black tea leaves and 1 cinnamon stick in a pan and bring to a simmer, stirring until the sugar dissolves.

Step 3: Add the peeled eggs and simmer gently for 1 hour, turning now and then. Keep the heat low so the sauce never boils hard.

Step 4: Lift the eggs onto a wire rack and dry them in front of a fan for 1 hour, until the surface feels dry and slightly tacky. Common mistake: skipping the drying; the eggs stay soft and brown instead of shrinking and turning black.

Step 5: Return the eggs to the sauce and simmer for 1 hour, then dry again for 1 hour. Repeat the braise-and-dry cycle 3 more times (about 8 hours in all), topping up the sauce with a splash of water if it gets very thick.

Step 6: After the last braise, simmer the eggs uncovered for 10 minutes, rolling them, until the sauce is syrupy and clings. They are ready when they are black, glossy, shrunk by about a third and firm and springy to bite.

Step 7: Cool and dry the eggs on the rack for 30 minutes, then keep them covered in the fridge for up to 5 days. Eat cold or at room temperature.