Image credit to: Katie Bornn
Bring a large saucepan of water to a boil. Add noodles and cook according to package directions. Drain, rinse with cold water and set aside.
Whisk 6 Tbsp water, mirin, soy sauce and cornstarch in a small bowl. Set aside
Whisk red pepper paste, garlic and hot water together in a medium bowl.
Slice chicken into thin strips and place in bowl with red pepper paste. Let marinate in the fridge.
Heat oil in a large skillet over medium heat. Add onion and cook, stirring occasionally, until beginning to soften, 2 to 3 minutes. Add bok choy and carrots, stirring occasionally, until beginning to soften, about 5 minutes.
Add the chicken and red pepper marinade; cook, stirring, until the chicken is just cooked through, about 5 minutes.
Whisk the cornstarch mixture again, add it to the pan and bring to a boil. Cook, stirring, until the sauce has thickened, 2 to 4 minutes. Serve over the noodles. Garnish with sesame seeds.