1. In a bowl, whisk together the chicken stock, peanut butter, soy sauce, brown sugar, dried mustard, red pepper flakes, and sliced scallions. Reserve some scallions for garnishing at the end.
2. In a large skillet, sauté the chicken strips in sesame oil until done. Add the broccoli and ginger cubes and continue to sauté until fully cooked.
3. Pour the sauce over the chicken and broccoli mixture. Bring to a boil. Add the raw egg noodles directly into the pan. Cover the pan and cook four to five minutes until the egg noodles have softened and are coated in the sauce with the broccoli and the chicken. The starches from the egg noodles will thicken the sauce.
4. Add the snow peas to the lo mein. Top with remaining scallions and sesame seeds.