How to Make It
Combine chicken, 2 tablespoons of the cornstarch, 1 tablespoon of the teriyaki sauce, 1 teaspoon of the garlic, and red pepper in a bowl; toss well. Heat a large nonstick skillet over medium-high heat. Add oil to pan; swirl to coat. Add chicken mixture to pan; cook 6 minutes, browning on all sides. Stir in 1/2 cup of the broth, scraping pan to loosen browned bits. Transfer chicken mixture to the inner pot of a 6-quart Instant Pot®.
Combine remaining 1 1/2 cups broth, peanut butter, remaining 1 tablespoon cornstarch, remaining 1 tablespoon teriyaki sauce, and remaining 1 teaspoon garlic in a bowl; pour over chicken mixture.
Close and lock the lid of the Instant Pot®. Turn the steam release handle to "Venting" position. Press [Slow Cook], and use [Adjust] to select "More" mode. Press [-] or [+] to choose 1 hour 30 minutes cook time. Stir in peas and carrots; repeat slow cook procedure, choosing 30 minutes cook time. When time is up, peas should be crisp-tender.
While peas and carrots cook, cook pasta according to package directions, omitting salt and fat; drain. Add cooked spaghetti to chicken mixture in cooker; toss well. Sprinkle with scallions and peanuts; serve with lime wedges, if desired.