Step 1

Place 1 cup tamari or soy sauce, 1/2 cup packed light brown sugar, and 1/4 cup mirin in a small saucepan. Bring to a boil over medium-high heat, stirring occasionally until sugar is dissolved, about 2 minutes. Reduce the heat to medium-low. Simmer until the sauce is glossy and thick enough to lightly coat the back of a spoon, about 15 minutes.

Step 2

Taste and add more sugar as needed. Remove the saucepan from the heat and let cool to room temperature, about 20 minutes. Meanwhile, cut 1 large broccoli crown into bite-sized florets (about 3 cups) and trim 18 young carrots if needed.

Step 3

Peel 1 (1-inch) piece ginger and thinly slice. Smash and peel 4 garlic cloves. Place the ginger, garlic, and 3/4 cup of the teriyaki sauce in a blender. Blend until smooth to make the marinade, about 30 seconds. Set aside the remaining teriyaki sauce for serving, or refrigerate in an airtight container if you’re cooking the chicken the next day.

Step 4

Place 3 pounds boneless, skinless chicken thighs in a 1-gallon zipper-lock bag or large food container, add the teriyaki marinade, and flip the chicken until each piece is well coated. Seal the bag or cover the container and marinate in the refrigerator for at least 2 hours or up to 24 hours.

Step 5

Rinse and cook 3 cups sushi rice according to package instructions. If the teriyaki sauce has been refrigerated, let it sit out at room temperature.

Step 6

Arrange an oven rack about 6 inches from the broiler element and set the broiler to high heat. Fit a wire rack in a rimmed baking sheet. Place the chicken in an even layer on the rack; discard the marinade. Broil until the chicken is lightly charred on top, 4 to 6 minutes. Flip the chicken and and broil until the second side is lightly charred and an instant-read thermometer inserted into the thickest piece registers at least 165ºF, 4 to 6 minutes more. (Alternatively, grill the chicken on an outdoor grill over direct, medium-high heat.)

Step 7

While the chicken cooks, fill a steamer or large pot with a steamer insert with 1 to 2 inches water. Bring to a boil over medium-high heat. Reduce the heat to maintain a lively simmer.

Step 8

When the chicken is ready, transfer to a clean cutting board, tent with aluminum foil, and let rest for 5 minutes. Meanwhile, place the broccoli and baby carrots in the steamer in an even layer, cover, and steam until crisp-tender, about 5 minutes.

Step 9

Cut the chicken crosswise into 1/2-inch pieces. Serve with steamed rice, vegetables, and reserved teriyaki sauce.