Whisk the soy sauce, pineapple juice, honey, ginger, garlic, sesame oil, and salt together in a bowl. Pour half of this mixture over your cubed chicken in a separate bowl, then cover and refrigerate for at least an hour. Save the other half of the marinade in the fridge, since that's what becomes your glaze later.
While the chicken marinates, drop your wooden skewers into a tall glass or dish of warm water. Let them soak for about 30 minutes so they don't catch fire or burn under the oven's heat. This is also a great window of time to chop your peppers and onion.
Once the chicken has marinated and the skewers are softened, start alternating chicken, pineapple, onion, and pepper onto each skewer. Leave about an inch of bare skewer on each end so they're easy to pick up and turn. Discard any leftover raw marinade the chicken sat in.
Arrange the kabobs on a lined baking sheet and slide them into a 425°F oven. Bake for 12-15 minutes, flipping halfway through, until the chicken hits 165°F internally. If you want a little char, run them under the broiler for the final 2-3 minutes.
While the kabobs bake, pour your reserved marinade into a small saucepan over medium-high heat. Whisk the cornstarch with a splash of water, then stir it into the simmering sauce. Keep stirring until it thickens enough to coat the back of a spoon.
Once the kabobs come out of the oven, brush them generously with the warm glaze. The glossy coating adds both flavor and a nice sheen that makes the dish look extra appetizing on the plate.