Place the chicken carcass and the whole chicken leg to a pot. Add the quartered onions, crushed garlic cloves, chopped ginger, fish sauce, soy sauce, and peppercorns to the pot. Add the water, bring to a boil and boil for 3 minutes.

Skim off the foam, cover leaving a small crack open, turn the heat down to low and simmer the stock for 2 hours. Remove the lid and simmer for another 30 minutes to reduce the stock. Skim off any froth or fat from the surface of the stock.

Strain the stock. Use the chicken meat for other dishes.

Bring a large pot of water to a boil. Add some salt and blanch the cabbage leaves for 2 minutes or until pliable. Remove with a slotted spoon, refresh under cold water and drain well.

Chop the mushrooms, the whites of the green onions, and the Thai chili very finely. Place them in a bowl together with the minced pork. If necessary shell and devein the shrimps. Chop them very finely as well and add them to the bowl. Add the fish and the soy sauce. Mix well.

The recipe makes about 10 cabbage rolls. To make the rolls, place one cabbage leaf on the working surface. If the leaf is torn use two cabbage leaves to form the roll. Place a tenth of the filling about 1 cm/ ½ inch from the bottom of the leaf. Fold the bottom edge over the filling, fold in the left and right side, and roll the leaf.

Pour about 1 liter/ 4 cups of the broth into a deeper pan. Chop the ginger roughly and add it to the pot as well. Bring the stock to a boil, turn the heat down to low, and carefully place the cabbage rolls into the pot. Add the extra mushrooms, if desired.

Let simmer for about 20 minutes or until the filling is cooked through. Sprinkle with the chopped spring onion greens, chopped parsley or coriander and serve immediately.