Prepare noodles as per packet instructions.
In a small cup or jar, mix together mirin, soy sauceor tamari, oyster sauce, chicken broth, and cornflour and mix together well.
Heat oil in a wok or large skillet over medium heat. Add onion and saute for a couple of minutes then add carrot and corn kernels and green beans cook for a minute. Add garlic and ginger cook for a minute then add chicken mince. Cook for a few minutes then add the mushrooms until just soft and chicken is cooked through.
Chop up the noodles into small pieces and stir through. Add sauce and stir through for cook for a minute or two.
Transfer filling into a serving bowl and stir through the sesame oil. Put lettuce leaves onto a serving plate with the peanuts and coriander on the side to serve. Everyone can fill and enjoy their own lettuce cup!