Prepare the oven: Position a rack in the center of the oven. Place a large rimmed baking sheet on the rack and preheat the oven to 425°F (220°C). Allow the pan to heat thoroughly so the chicken and vegetables sizzle on contact.

Make the glaze: While the oven heats, combine the tamari, chicken broth, honey, sesame oil, garlic, ginger, and sriracha in a small bowl. Whisk until the honey is fully dissolved and the mixture is smooth.

Prepare the ingredients: Cut the chicken into uniform 1 inch (2.5 cm) bite sized chunks. Cut the bell peppers into 1 inch (2.5 cm) pieces. Trim the scallions, thinly slicing the dark green tops for garnish and cutting the white and light green parts into 2 inch (5 cm) lengths.

Coat the chicken: Place the chicken chunks in a large mixing bowl. Pour about half of the prepared glaze over the chicken and toss until every piece is evenly coated.

Coat the vegetables: In a separate mixing bowl, add the red and yellow bell peppers, snap peas, and the 2 inch (5 cm) scallion pieces. Pour the remaining glaze over the vegetables and toss to coat evenly.

First roast: Carefully remove the hot baking sheet from the oven. Working quickly, arrange the glazed chicken in a single layer on the pan. Return the pan to the oven and roast for 12 to 15 minutes, until the edges of the chicken begin to brown.

Combine and finish: Remove the pan from the oven. Add the glazed vegetables to the pan around the chicken and gently stir everything together into an even layer. Return the pan to the oven and roast for 10 to 12 minutes more, or until the chicken is cooked through (reaching an internal temperature of 165°F / 74°C) and the vegetables are crisp tender.

Serve: Remove from the oven and immediately garnish with the reserved sliced scallion greens, fresh cilantro, and toasted sesame seeds. Serve hot.