Turn Instant Pot onto sauté and wait for it to get hot. Add the sesame oil, garlic, onion, salt, pepper, and chicken. Cook until the chicken turns white and the onion is soft.
Turn Instant Pot off. Break rice stir-fry noodles in half and layer in the pot on top of the chicken mixture. Add the chicken stock, lemon juice, rice wine vinegar, Hosin Sauce, and soy sauce. Don't stir.
Layer all veggies and place lid on Instant Pot, placing the vent onto the sealing position. Select manual high pressure (or the pressure cook button on newer models) for 4 minutes.