In a large mixing bowl, combine the sugar, fish sauce, honey, and pepper. Mix until the sugar has dissolved. Add the bashed spring onion, garlic, and sliced pork neck.
Coat the pork well then enclose the flavours with the vegetable oil. Let the mixture marinate in the refrigerator for 2 hours or overnight, for a better result.
Preheat a grill on medium to high heat. Thread the pork onto the skewers and char grill on medium to high heat for 1 to 2 minutes on each side, or until brown and cooked through.
Divide the cooked vermicelli noodle among 4 to 6 bowls, add the mint, perilla leaves, Vietnamese mint, cucumber, and bean sprouts, then add 1 to 2 pork skewers to each bowl.
Dress each bowl with 2 tablespoons of dipping fish sauce, a teaspoon of spring onion oil, and sprinkle fried Asian shallots and crushed peanuts on top.
To make the dipping fish sauce: Combine the fish sauce, vinegar, sugar, and water in a saucepan and place on medium heat. Stir well and cook until just before boiling point is reached, then allow to cool. To serve, finely chop the garlic and chile and stir through with the lime juice.