Bring a large pot of water to a boil. Add the soba noodles and cook according to the package instructions, usually around 4 to 5 minutes. Once al dente, drain the noodles in a colander and rinse under cold water to stop the cooking process and prevent sticking. Set aside.
While the noodles cook, thinly slice the chicken breast, bell peppers, chili pepper, red onion, and carrot. Halve the baby corn lengthwise and thaw the frozen green beans. Prepping everything upfront makes the stir-frying smooth and efficient.
Heat 1 teaspoon of sesame oil in a hot wok or large skillet over medium-high heat. Add the sliced chicken breast and cook for about 3-4 minutes until it is browned and cooked through, stirring occasionally. Remove the chicken from the wok and set aside.
Add the remaining 2 teaspoons of sesame oil to the wok. Toss in the red onion, yellow and red bell peppers, chili pepper, carrot, baby corn, and green beans. Stir fry for 4-5 minutes until the vegetables are tender-crisp and fragrant.
Return the cooked chicken to the wok with the veggies. Add the soba noodles and pour in 6 teaspoons of soy sauce. Toss everything gently but thoroughly to coat the noodles and ingredients evenly with the sauce. Stir fry for another 1-2 minutes to heat through.
Once everything is heated and combined beautifully, transfer the stir fry to plates or bowls. This dish pairs wonderfully with a side of steamed rice or as a standalone meal.