To make the spice paste: finely dice all the ingredients (except the oil). Heat the oil, add the spice paste and fry over a medium heat. Remove from the stove and allow to cool. Combine the remaining ingredients except for the banana leaves and mix well until the chicken and mushrooms have a good coating of spice mix. Briefly place the individual banana leaves on the hot Tepan cooktop. Place 3 tablespoons of the chicken mix on each banana leaf and roll up. Use bamboo skewers or toothpicks to seal the ends. Steam the parcels in the bamboo basket for four minutes then grill on the Tepan for three minutes over a low heat.