Heat peanut oil in a large skillet over medium heat. Add garlic and sesame seeds and sauté 3-5 minutes or until seeds are golden brown. Reduce heat to medium-low; add oil, sugar, vinegar, soy sauce, crushed red pepper, and chicken chunks and heat for 2 minutes.
Add to linguine and toss until well combined. Sprinkle with chopped scallions and serve immediately, or cover and chill until ready to serve. Can be served cold or rewarmed.