Thoroughly wash the shrimps by sprinkling salt over them, and rinse under running water till no longer viscous to the touch. Dry them with paper towel
Roughly cut the shrimps to small pieces, put them in a bowl with the all the ingredients except for the mayonnaise and oil. Mix well to blend. Put the mixture in the food processor and blend until a coarse paste is formed. If using a Magic Bullet, process by batch by quick pulses to achieve a coarse paste. Put the shrimp paste mixture in a bowl and add the mayonnaise and oil, and mix well. Cover and let rest for 20 to 30 minutes.
Meanwhile, prepare the scallion oil. Chop the bunch of scallion and put in a microwave-safe bowl. Add a pinch of sugar and a pinch of salt, and 2 tablespoons of oil. Heat in the microwave for 30 seconds. Let cool.
Cut 4 sugarcanes into 4 lengthwise to make 16 skewers. Reserve the rest for another use (they can be wrapped and frozen).
Set a bowl of water, 2 oven-safe large plates, the sugar cane skewers, and the shrimp paste mixture bowl on the kitchen counter. Wet your left (or secondary) palm with water, put 2 to 3 tablespoons of shrimp paste on the palm and a stick of sugar cane in the center. Wrap the shrimp paste around the sugar cane and lightly squeeze to wrap the paste tightly around the sugar cane. Continue until the shrimp paste is finished. Depending on how thick the shrimp paste is, you should have 14 to 16 skewers.
Lightly oil the 2 oven-safe plates. Display 7 to 8 skewers on each plate. Microwave for 1 minute on each side, total 2 minutes for each plate.
Take 1 tablespoon from the scallion oil made earlier, and put in a small bowl.Reserve the rest of the scallion and oil for garnish. Lightly brush the scallion oil over each skewer before grilling, to prevent from sticking to the grilling surface.
Grill over medium high heat for 6-8 minutes, turning the skewers every couple of minutes so all sides are grilled evenly.
Meanwhile, prepare the Banh Hoi (or rice vermicelli bundles) according to package instructions. Spread the scallions (from the scallion oil mix) evenly over each cooked bundle
Wash and dry the lettuce and Asian herbs and display on a platter
Prepare the Nuoc Cham (please see my recipe via the link at the end of the post)
Serve the Chao Tom, Grilled Shrim Skewers, with the Banh Hoi, Lettuce and fresh herbs and enjoy immediately.