For the Kung Pao Sauce
In a medium sauce pan, whisk together the chicken stock and cornstarch until the cornstarch has fully dissolved. Stir in the soy sauce, sherry, red chili paste, sugar, red wine vinegar and sesame oil. Bring to a boil over medium high heat, stirring continuously. Reduce the heat and simmer the sauce until its thick enough to coat the back of a spoon (15 minutes). Set aside.
For the Chicken
In a medium Ziplock bag, mix cornstarch and salt. Meanwhile in a large nonstick skillet, heat the olive oil over medium high heat until hot. Add the chicken pieces to the cornstarch mixture. Toss to coat. Add chicken to skillet and cook until well-browned (8 minutes). Add pepper flakes and peanuts to skillet, cook for 30 seconds; add garlic and scallions. As soon as garlic browns (30 seconds), add the Kung Pao sauce. Stir until combined.
For the Pasta
Heat a large pot of water. Bring to a boil. Cook pasta according to package directions.
When the pasta is ready, drain it well and toss it with the sauce thoroughly.