Mix the finely sliced leeks with the corn and rice in the bottom of an ovenproof casserole. Add the cardamon seeds and peppercorns, then lay the chicken joints on top. Pour over the stock and tuck the lemon slices around the chicken joints. Cover the casserole and bake in a moderately cool oven (150ºC/300ºF/Gas 3) for 1½ - 2 hours or till the liquid is absorbed and the rice and chicken are quite cooked. Check after an hour and add more liquid if necessary. The chicken joints should be sitting on a deliciously scented and flavoured bed of rice.
Serve direct from the casserole with a green vegetable or salad.