Position an oven rack 6 inches from the broiler element and preheat the oven to 400°F.
In a medium bowl, whisk together the vinegar, honey, ketchup, melted butter, garlic salt, and garlic until well combined.
Place the chicken thighs on one side of a sheet pan and pat them dry. Drizzle with the oil and sprinkle with the salt and pepper. Bake for 15 minutes.
Remove from the oven and place the pineapple and bell peppers on the other end of the pan. Baste the chicken thighs with 1/2 cup of the sauce and bake for 10 minutes.
Turn the oven to broil (do not remove the pan) and broil until the chicken is charred in several places, 8 to 10 minutes.
Transfer the chicken, pineapple, and peppers to a large bowl and toss with 1/2 cup of the remaining sauce.
Top with fresh parsley and sesame seeds. Serve over rice with the remaining sauce on the side.
Store in an airtight container in the refrigerator for 3 to 5 days.