Heat the oven to 400°F. In a small bowl, toss quartered mushrooms and red peppers with the sesame oil and sriracha. Spread out on a baking sheet. While you make the Chicken Lo Mein, bake for 15 minutes until tender and blistered in spots.
In a small bowl, stir the soy sauce, hoisin sauce, sesame oil, and hot water together. Set aside.
Bring a large amount of salted water to a boil. Add the noodles and cook until tender, usually around 4 minutes, but check the package directions for the noodles you are using. Drain the noodles and toss with sesame oil to prevent sticking.
Heat a wok or large skillet over medium-high heat. Once hot, add the vegetable oil once that's hot, add the chicken. Cook until the chicken is just barely cooked through, 5 to 6 minutes, stirring frequently. (The chicken will continue to cook with the vegetables, so it's ok if it seems a little undercooked right now.)
When chicken is cooked, add cabbage and carrots, and continue to stir and cook until the veggies wilt and the liquid they release is mostly evaporated, 2 to 3 minutes.
Add noodles along with sauce and stir with the chicken and veggies to combine. The sauce should coat the noodles and other ingredients. If the dish seems too dry, add more water. Taste and adjust the flavor to your liking. It might need another dash of soy sauce, for example.
Serve the Chicken Lo Mein topped with scallions, sesame seeds, and roasted veggies (optional). Leftovers can be stored in the fridge for 3 to 4 days and will reheat beautifully in the microwave.
Notes
Chef created this recipe based on the dish title and common cooking methods. Please review and adjust to taste.