Place the pork cubes in a 1-gallon zip top bag. Combine the marinade ingredients in a 2-cup measuring cup or medium bowl and whisk until the sugar dissolves. Pour into the bag and seal, squeezing out as much air as possible. Squish everything around to ensure even coat-age, then refrigerate for at least 4 hours or up to overnight.
When ready to cook, remove the pork from the bag (reserving the marinade), and place on a rack over a sheet pan (or paper towels), to catch any drips. Skewer 5-6 cubes of pork per stick and set aside until ready to grill.
Pour the reserved marinade into a 1-quart saucepan over medium-high heat and boil for 10 minutes until slightly thickened and reduced by half.
Prepare a small charcoal grill for direct heat. While you wait for the coals, prepare the dipping sauce.
Combine the cane vinegar, soy sauce, sugar, red onion, garlic, and chili in a small bowl. Set aside until ready to serve.
When the coals are good and hot, arrange the pork skewers on the grill and cook for 8-10 minutes, brushing with the reduced marinade, until nicely charred and cooked through. Turn them often to create even charring. (I tend to flip mine almost every 30 seconds.)
Remove to a platter and serve immediately with the dipping sauce.
Note: My favorite grill for satay, or kushiyake is known as a Konro. Frequently seen in yakitori restaurants, it's basically a fairly narrow box made of diatomaceous earth. Konros can be used with grill grates, (which I prefer) or, if you're using flat skewers (which prevent rolling) you can simply rest the ends on the sides of the grill. I have two Konros and I love the short one (a mere 12" x 9") so much that I've written several sonnets to it. When loaded with Japanese binchotan charcoal, it's simply the perfect grill for small pieces of food and skewers.If you have yet to acquire a Konro, I suggest building a small charcoal fire on your grill's coal grate, between four fireplace bricks arranged thusly...and topped with a small, steel cooling grate. In any case the fire should be medium hot so that a hand held an inch over the grate can only be kept there for a second, (unless you're like Gary Busey's character in Lethal Weapon, in which case I can't help you). If you don't want to mess with the bricks fine...weave two folded over (2-ply) strips of heavy-duty aluminum foil through your grill grates, parallel to each other at a distance that matches the length of the skewers taken up by the meat. Lay a small metal cooling rack on top (so that the skewers don't fall through the grates) and cook over a hot fire. The foil should protect the ends of the skewers from full on combustion.And yet another note: Since they tend to float, I soak my skewers in a plastic water bottle. When I need one, I just open the lid and kinda pour them out. This is far more efficient than soaking in a loaf pan or baking dish.