Step 1: Build the Flavorful Rice Base - Preheat your oven to 375 degrees and set out a 9 by 13 baking dish. In a medium bowl whisk together the chicken broth, half of the Japanese BBQ sauce, soy sauce, sesame oil, rice wine vinegar, half the garlic powder, half the onion powder, half the red pepper flakes, and half the pepper. Give it a good stir until everything looks glossy and blended. This mixture is what gives the rice all that incredible flavor while it bakes.
Step 2: Layer the Rice and Vegetables - Pour that seasoned broth mixture into the baking dish. Add the white rice, chopped white green onion pieces, and shredded carrots. Stir everything together right in the dish so the rice is coated well. This step matters because you want all those flavors evenly distributed before the chicken goes on top.
Step 3: Season and Glaze the Chicken - In a separate bowl toss the chicken thighs with the remaining garlic powder, onion powder, red pepper flakes, and pepper. Nestle the chicken pieces right over the rice mixture. Then drizzle the remaining Japanese BBQ sauce over the top and use a spoon or brush to baste each piece well. This is where that sticky glazed finish starts.
Step 4: Cover and Bake Until Tender - Cover the baking dish tightly with foil. This is important because the rice needs that trapped steam to cook properly. Slide it into the oven and bake for 55 minutes. During that time the rice absorbs all the liquid and the chicken slowly turns tender and juicy.
Step 5: Broil for Caramelized Finish - Remove the foil and switch the oven to broil. Broil for about 5 minutes, just until the chicken gets glossy and slightly caramelized around the edges. Keep an eye on it because broilers move fast. That little finishing step gives it that irresistible takeout style look and flavor.
Step 6: Finish and Serve - Scatter the reserved green onion tops over everything before serving. I like to fluff the rice a little around the chicken before plating so every scoop gets some of that sauce soaked rice. It smells unbelievable at this point.