1, Grind the pork slices with 1/2 of the salt, 1/2 of the sugar and 1/2 of the fish sauce to a paste in a food processor and set aside.
2, Heat the oil in a wok or skillet over low heat until hot. Stir-fry the pork skin for about 5 minutes until crispy and golden brown. Remove and drain on paper towels.
3, Reheat the oil in the same wok or skillet over medium heat, stir-fry the crushed garlic until fragrant and golden brown, 1 to 2 minutes. Add the remaining salt, sugar and fish sauce, and simmer until the sauce is thick. Remove and set aside to cool.
4, Combine the pork paste, pork skin and ground roasted rice in a bowl. Pour in the sauce and mix until well blended.
5, Wet your hands, spoon 11/2 tablespoons of the mixture and shape it into a ball. Place the ball onto a piece of the banana leaf and shape it into a cube by flattening the sides with the back of a wet spoon, then top the cube with a slice of garlic and a slice of chili. Wrap by folding one end of the banana leaf over the filling and rolling it up tightly, then folding both ends inward to form a little square parcel. Tie the parcel securely with string. Repeat until all the mixture is used up.
6, Chill the wrapped sausages in the refrigerator for 2 days. Unwrap and serve with the Pickled Spring Onions.