Using a sharp knife and working from top to bottom, cut limes into quarters, making sure not to cut all the way through. Reserve any juices. Combine salt and peppercorns, stuff into limes and stand upright on a tray.
Combine remaining ingredients in a wide saucepan, add any reserved juices and bring to the boil. Place limes in the pan, cut side up, return to the boil, then cover and simmer over low heat until limes turn yellow (10 minutes). Remove pan from heat and allow to stand until cool (30-35 minutes).
Loosely layer limes into 2 sterilised 1-litre jars and pour the cooking liquid over them. Don’t worry if liquid does not cover limes; this will happen in time. Seal and store in a cool dark place for at least 2 weeks before using.
Note This recipe is from Serendip: My Sri Lankan Kitchen by Peter Kuruvita (Murdoch Books, $59.95, hbk). In editing these recipes for publication, we have made minor changes to bring them into Gourmet Traveller style.