In a small bowl, combine all sauce ingredients. Set aside.

In another small bowl, mix together 1 tablespoon peanut oil, cornstarch, soy sauce, and black pepper. Pour mixture over sirloin strips and let sit at room temperature for 10 minutes.

In a large pot of boiling water, blanch green beans and carrots for 5 minutes. Plunge into a bowl of ice water to stop cooking. Set aside.

Heat remaining 2 tablespoons peanut oil in a wok or a non-stick skillet over medium-high heat. Add garlic, ginger, and green onion. Stir-fry for 1 to 2 minutes, then add beef. Cook and stir beef until it has lost its redness. Add red bell pepper and cook for 2 minutes. Add blanched green beans and carrots. Reserving 1/2 cup sauce for fettuccine, add remaining peanut sauce to beef mixture. Cook until all vegetables are heated.

Add reserved peanut sauce and chopped peanuts to hot fettuccine. Stir to combine. Serve beef mixture over hot noodles.