Cook the Udon Noodles: Bring a pot of water to a boil and cook the udon noodles according to package instructions. Drain and set aside.
Prepare the Chicken: In a large pan or wok, heat the vegetable oil over medium-high heat. Add the sliced chicken and cook for about 5-7 minutes until golden brown and cooked through. Remove the chicken from the pan and set it aside.
Sauté the Vegetables: In the same pan, add the red bell pepper, broccoli, ginger, and garlic. Stir-fry for 3-4 minutes until the vegetables are tender-crisp.
Combine & Flavor: Return the cooked chicken to the pan along with the cooked udon noodles. Pour the teriyaki sauce, soy sauce, and sesame oil over the mixture. Toss everything together to combine and heat through for another 2-3 minutes.
Garnish & Serve: Remove the pan from heat and sprinkle chopped spring onions and sesame seeds over the stir fry. Mix gently before serving.
Notes
Serve the stir fry in bowls and top with additional sesame seeds and spring onions for a vibrant, colorful dish.