In a small bowl, whisk together the chicken broth, ¼ cup soy sauce, brown sugar, sesame oil, gochujang, sesame seeds, red pepper flakes, black pepper, and cornstarch. Mix until smooth and set aside.

Bring a large pot of water to a boil. Cook the glass noodles according to the package directions until tender. Drain thoroughly and set aside.

Heat 2 tablespoons of oil in a large skillet over medium-high heat. Add the sliced mushrooms and cook for about 2 minutes. Stir in the remaining 2 tablespoons soy sauce and continue cooking for another 2 minutes until tender and lightly browned. Transfer to a plate and set aside.

Add the remaining tablespoon of oil to the skillet. Add the ground chicken and cook, breaking it apart with a spoon, until fully cooked and no longer pink. Season with salt.

Stir in the carrot, bell pepper, and sliced white parts of the green onions. Cook for about 3 minutes until slightly softened. Add the minced garlic and cook for another 1 to 2 minutes until fragrant.

Whisk the sauce again, then pour it into the skillet. Stir well, scraping up any browned bits from the bottom of the pan. Let it simmer for 3 to 5 minutes, or until the sauce thickens.

Return the cooked mushrooms and drained noodles to the skillet. Using tongs, gently toss everything together until evenly coated in the sauce and heated through.

Divide into bowls and top with chopped roasted peanuts, extra sesame seeds, and the green parts of the onions before serving.