Spiralize the zucchini and pat dry with paper towels to remove excess moisture.
Season chicken pieces with salt and pepper.
Heat 1 tablespoon of olive oil in a large skillet or wok over medium-high heat.
Add chicken to the skillet and cook until browned and cooked through, approximately 5 to 7 minutes. Remove chicken and set aside.
Add the remaining 1 tablespoon of olive oil to the same skillet. Add minced garlic and red pepper flakes; sauté for 30 seconds until fragrant.
Add zucchini noodles to the skillet and toss frequently for 2 to 3 minutes until slightly softened but still al dente.
Return the cooked chicken to the skillet.
Pour in the soy sauce and sesame oil.
Toss all ingredients together for 1 minute until well combined and heated through.
Garnish with sesame seeds and serve immediately.