Trim the fat off the chicken thighs and cut into thick slices, about 2" x 2". Put them in a bowl with the teriyaki sauce, stir to coat the chicken, cover and refrigerate overnight to marinate.
Get your gas or charcoal grill ready! Layer the chicken, pineapple, carrots, and onion onto 4 skewers (see photos for example) and place on the grill over medium-high heat. Cook until the chicken looks slightly burned on the edges, 10-15 minutes. Be careful not to cook too long, the chicken should be tender and juicy, not dry. Have some rice on the side and extra teriyaki sauce on hand if you'd like!