Instructions:

1. Prepare the Udon Noodles: If using fresh udon noodles, cook them according to the package instructions. If using frozen, boil them until heated through. Drain and set aside.

2. Make the Teriyaki Sauce: In a small bowl, combine soy sauce, honey, rice vinegar, and sesame oil. Stir until well mixed. Add the cornstarch slurry to thicken the sauce and set aside.

3. Cook the Chicken: In a large skillet or wok, heat a tablespoon of oil over medium-high heat. Add the sliced chicken breast and cook until browned and cooked through, about 5-7 minutes. Remove the chicken from the skillet and set aside.

4. Stir-Fry the Vegetables: In the same skillet, add a little more oil if necessary, then add minced garlic and ginger, sautéing for about 30 seconds until fragrant. Add the broccoli, bell peppers, and carrots. Stir-fry for about 5 minutes, or until the vegetables are tender but still crisp.

5. Combine Everything: Return the cooked chicken to the skillet with the vegetables. Pour the teriyaki sauce over the mixture and stir well to combine. Cook for another 2-3 minutes, allowing the sauce to thicken and coat the chicken and vegetables.

6. Add Udon Noodles: Gently toss the cooked udon noodles into the skillet, making sure they are well coated with the sauce and mixed with the chicken and vegetables. Heat through for another minute.

7. Serve: Transfer the teriyaki chicken udon to serving bowls. Garnish with chopped green onions, sesame seeds, and fresh cilantro if desired.