Step #1 Place split chicken breasts In a large-ish bowl; add lime & water.
Step #2 Let stand while you prepare sauce.
Step #3 Combine allspice, ginger, pepper & garlic in a mortar & mash to a paste with a pestle or grind in a food processor/blender fitted with the metal blade.
Step #4 Add cayenne, cardamom & cloves & mix again set aside.
Step #5 Heat a large, deep sauté pan or casserole over med-heat/flame.
Step #6 Without using any fat, add onions & stir constantly until some moisture has been released.
Step #7 Cook, stirring often, until onions are soft & somewhat golden, 30 to 40 mins.
Step #8 If the skillet gets too dry, add 1 to 2 tbsps butter.
Step #9 This process is slow, but eventually, onions will take on a golden color.