Spiralize the zucchini into noodles. Place in a colander, toss with a pinch of salt, and let sit for 10 minutes. Squeeze gently with a towel to remove excess moisture.

In a small bowl, whisk together the soy sauce, chicken broth, toasted sesame oil, ginger, red pepper flakes, and cornstarch slurry (if using). Set aside.

Heat oil in a large skillet or wok over medium-high heat. Add cubed chicken, season lightly with pepper, and cook until golden brown and cooked through (about 5-6 minutes). Remove chicken to a plate.

Lower heat to medium. Add minced garlic and the white parts of the green onions to the skillet. Sauté for 30-60 seconds until fragrant.

Pour the sauce mixture into the skillet and let it simmer for 1-2 minutes until slightly thickened.

Return the cooked chicken to the skillet, tossing to coat completely in the sauce.

Add the prepared zucchini noodles to the skillet. Toss gently with tongs for 1 to 2 minutes just to warm through. Do not overcook.

Remove from heat immediately. Garnish with the green parts of the green onions and serve hot.