Juice and rind of 1 large lemon mixed with 2 tbsps of brown sugar.Coat kumara with sugar mixture; lay flat in roasting pan and dot with butter.
Turn kumara and keep coated with mixture. Cook at 180 till tender.
Sprinkle with lemon pepper and a splash of lemon oil.
Note: To keep pan clean line a layer of tinfoil in the bottom of pan. A mix of three different kumara gives a nice colour combination.